Category Archives: C#

C#.Algo.SymbolGraph

Posted on 03.10.2017 by Stanislav_Panteleev

Git SymbolGraph.cs // switched to C# Dictionary in spite of SequentialSymbolTable

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SymbolGraphExample
{


    public class SymbolGraph
    {
      //  private SequentialSearchST<String, int> st;  // string -> index 
        private Dictionary<string, int> d;
        private string[] keys;           // index  -> string
        private Graph graph;             // the underlying graph

        public SymbolGraph(string filepath, char delimiter)
        {
            //st = new SequentialSearchST<String, int>();
            d = new Dictionary<string, int>();          

            try
            {
                using (StreamReader sr = new StreamReader(filepath))
                {
                    while (sr.Peek() >= 0)
                    {
                        string s = sr.ReadLine();
                        string[] substrings = s.Split(delimiter);
                        foreach (var substring in substrings)
                        {
                            //if (!st.contains(substring))
                            if (!d.ContainsKey(substring))
                            {
                                //st.put(substring, st.size()+1);
                                int c = d.Count;
                                d.Add(substring, c);
                                //Console.WriteLine(substring+" "+st.size());
                                Console.WriteLine(substring + " " + c);
                                //Console.WriteLine();
                                //st.ConsoleDisplay();
                            }
                        }
                        
                    }
                }
            }

            catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

            // inverted index to get string keys in an aray
            //keys = new string[st.size()];
            keys = new string[d.Count];
            foreach (KeyValuePair<string, int> entry in d)
            {
                // do something with entry.Value or entry.Key
                keys[entry.Value] = entry.Key;
            }

            //test
            //foreach (string k in keys) Console.WriteLine(k); 

            /* deprecated
            foreach (string name in st.keys())
            {
                keys[st.get(name)] = name;
            }
            */

            // building graph in second reading file
            // graph = new Graph(st.size());
            graph = new Graph(d.Count);
            try
            {
                using (StreamReader sr = new StreamReader(filepath))
                {
                    while (sr.Peek() >= 0)
                    {
                        string s = sr.ReadLine();
                        string[] substrings = s.Split(delimiter);
                        //int v = st.get(substrings[0]);
                        //int v = d.FirstOrDefault(x=>x.Key== substrings[0]).Value;   //st.get(substrings[0]);
                        int v = d[substrings[0]];
                        for (var i = 1; i < substrings.Length; i++)
                        {
                            //int w  -1;
                            //int w = d.First(x => x.Key == substrings[i]).Value;  //st.get(substrings[i]);
                            int w = d[substrings[i]];
                            //if (w!=v)
                                graph.addEdge(v,w);
                        }                        
                    }
                }
            }

            catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

        }
        /**
 * Does the graph contain the vertex named {@code s}?
 * @param s the name of a vertex
 * @return {@code true} if {@code s} is the name of a vertex, and {@code false} otherwise
 */
        public bool contains(String s)
        {
            // return d.FirstOrDefault(x => x.Key == s).Key!=null; //st.contains(s);
            return d.ContainsKey(s); //st.contains(s);
        }
        /**
   * Returns the integer associated with the vertex named {@code s}.
   * @param s the name of a vertex
   * @return the integer (between 0 and <em>V</em> - 1) associated with the vertex named {@code s}
   */
        public int indexOf(String s)
        {
            return d.FirstOrDefault(x => x.Key == s).Value;//st.get(s);            
        }
        /**
 * Returns the name of the vertex associated with the integer {@code v}.
 * @param  v the integer corresponding to a vertex (between 0 and <em>V</em> - 1) 
 * @throws IllegalArgumentException unless {@code 0 <= v < V}
 * @return the name of the vertex associated with the integer {@code v}
 */
        public String nameOf(int v)
        {
            validateVertex(v);
            return keys[v];
        }
        /**
 * Returns the graph assoicated with the symbol graph. It is the client's responsibility
 * not to mutate the graph.
 * @return the graph associated with the symbol graph
 */
        public Graph getGraph()
        {
            return graph;
        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        private void validateVertex(int v)
        {
            int V = graph.V;
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }

        public string toString()
        {
            StringBuilder s = new StringBuilder();
            s.Append(graph.V + " vertices, " + graph.E + " edges " + "\n");
            
            for (int v = 0; v < graph.V; v++)
            {
                s.Append(nameOf(v) + ": ");
                foreach (int w in graph.adjVerticles(v))
                {                    
                    s.Append(nameOf(w) + " ");
                }
                s.Append("\n");
            }
            return s.ToString();
        }

    }
}

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using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SymbolGraphExample

{

public class SymbolGraph

{

// private SequentialSearchST<String, int> st; // string -> index

private Dictionary<string, int> d;

private string[] keys; // index -> string

private Graph graph; // the underlying graph

public SymbolGraph(string filepath, char delimiter)

{

//st = new SequentialSearchST<String, int>();

d = new Dictionary<string, int>();

try

{

using (StreamReader sr = new StreamReader(filepath))

{

while (sr.Peek() >= 0)

{

string s = sr.ReadLine();

string[] substrings = s.Split(delimiter);

foreach (var substring in substrings)

{

//if (!st.contains(substring))

if (!d.ContainsKey(substring))

{

//st.put(substring, st.size()+1);

int c = d.Count;

d.Add(substring, c);

//Console.WriteLine(substring+" "+st.size());

Console.WriteLine(substring + " " + c);

//Console.WriteLine();

//st.ConsoleDisplay();

}

catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

// inverted index to get string keys in an aray

//keys = new string[st.size()];

keys = new string[d.Count];

foreach (KeyValuePair<string, int> entry in d)

{

// do something with entry.Value or entry.Key

keys[entry.Value] = entry.Key;

}

//test

//foreach (string k in keys) Console.WriteLine(k);

/* deprecated

foreach (string name in st.keys())

{

keys[st.get(name)] = name;

}

// building graph in second reading file

// graph = new Graph(st.size());

graph = new Graph(d.Count);

try

{

using (StreamReader sr = new StreamReader(filepath))

{

while (sr.Peek() >= 0)

{

string s = sr.ReadLine();

string[] substrings = s.Split(delimiter);

//int v = st.get(substrings[0]);

//int v = d.FirstOrDefault(x=>x.Key== substrings[0]).Value; //st.get(substrings[0]);

int v = d[substrings[0]];

for (var i = 1; i < substrings.Length; i++)

{

//int w -1;

//int w = d.First(x => x.Key == substrings[i]).Value; //st.get(substrings[i]);

int w = d[substrings[i]];

//if (w!=v)

graph.addEdge(v,w);

}

catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

}

/**

* Does the graph contain the vertex named {@code s}?

* @param s the name of a vertex

* @return {@code true} if {@code s} is the name of a vertex, and {@code false} otherwise

public bool contains(String s)

{

// return d.FirstOrDefault(x => x.Key == s).Key!=null; //st.contains(s);

return d.ContainsKey(s); //st.contains(s);

}

/**

* Returns the integer associated with the vertex named {@code s}.

* @param s the name of a vertex

* @return the integer (between 0 and V - 1) associated with the vertex named {@code s}

public int indexOf(String s)

{

return d.FirstOrDefault(x => x.Key == s).Value;//st.get(s);

}

/**

* Returns the name of the vertex associated with the integer {@code v}.

* @param v the integer corresponding to a vertex (between 0 and V - 1)

* @throws IllegalArgumentException unless {@code 0 <= v < V}

* @return the name of the vertex associated with the integer {@code v}

public String nameOf(int v)

{

validateVertex(v);

return keys[v];

}

/**

* Returns the graph assoicated with the symbol graph. It is the client's responsibility

* not to mutate the graph.

* @return the graph associated with the symbol graph

public Graph getGraph()

{

return graph;

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

private void validateVertex(int v)

{

int V = graph.V;

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

public string toString()

{

StringBuilder s = new StringBuilder();

s.Append(graph.V + " vertices, " + graph.E + " edges " + "\n");

for (int v = 0; v < graph.V; v++)

{

s.Append(nameOf(v) + ": ");

foreach (int w in graph.adjVerticles(v))

{

s.Append(nameOf(w) + " ");

}

s.Append("\n");

}

return s.ToString();

}

SymbolTable – doesn’t work to symbol graph because of contains method

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SymbolGraphExample
{
    class SymbolTable
    {
    }

    public class SequentialSearchST<Key, Value> : IEnumerable<Key> where Value:IComparable
    {
        private int n;           // number of key-value pairs
        private Node first;      // the linked list of key-value pairs

        // a helper linked list data type
        private class Node
        {
            public Key key { get; set; }
            public Value val { get; set; }
            public Node next { get; set; }

            public Node(Key key, Value val, Node next)
            {
                this.key = key;
                this.val = val;
                this.next = next;
            }
        }

        /**
  * Initializes an empty symbol table.
  */
        public SequentialSearchST()
        {
        }

        /**
   * Returns the number of key-value pairs in this symbol table.
   *
   * @return the number of key-value pairs in this symbol table
   */
        public int size()
        {
            return n;
        }
        /**
   * Returns true if this symbol table is empty.
   *
   * @return {@code true} if this symbol table is empty;
   *         {@code false} otherwise
   */
        public bool isEmpty()
        {
            return size() == 0;
        }

        /**
  * Returns true if this symbol table contains the specified key.
  *
  * @param  key the key
  * @return {@code true} if this symbol table contains {@code key};
  *         {@code false} otherwise
  * @throws IllegalArgumentException if {@code key} is {@code null}
  */
        public bool contains(Key key)
        {
            if (key == null) throw new ArgumentException("argument to contains() is null");            
            Value r = get(key);
            return (r.CompareTo(default(Value)) != 0);
            
        }
        /**
   * Returns the value associated with the given key in this symbol table.
   *
   * @param  key the key
   * @return the value associated with the given key if the key is in the symbol table
   *     and {@code null} if the key is not in the symbol table
   * @throws IllegalArgumentException if {@code key} is {@code null}
   */
        public Value get(Key key)
        {
            if (key == null) throw new ArgumentException("argument to get() is null");
            for (Node x = first; x != null; x = x.next)
            {
                if (key.Equals(x.key))
                    return x.val;
            }
            return default(Value);
        }
        /**
     * Inserts the specified key-value pair into the symbol table, overwriting the old 
     * value with the new value if the symbol table already contains the specified key.
     * Deletes the specified key (and its associated value) from this symbol table
     * if the specified value is {@code null}.
     *
     * @param  key the key
     * @param  val the value
     * @throws IllegalArgumentException if {@code key} is {@code null}
     */
        public void put(Key key, Value val)
        {
            if (key == null) throw new ArgumentException("first argument to put() is null");
            if (val == null)
            {
                delete(key);
                return;
            }

            for (Node x = first; x != null; x = x.next)
            {
                if (key.Equals(x.key))
                {
                    x.val = val;
                    return;
                }
            }
            first = new Node(key, val, first);
            n++;
        }
        /**
    * Removes the specified key and its associated value from this symbol table     
    * (if the key is in this symbol table).    
    *
    * @param  key the key
    * @throws IllegalArgumentException if {@code key} is {@code null}
    */
        public void delete(Key key)
        {
            if (key == null) throw new ArgumentException("argument to delete() is null");
            first = delete(first, key);
        }

        // delete key in linked list beginning at Node x
        // warning: function call stack too large if table is large
        private Node delete(Node x, Key key)
        {
            if (x == null) return null;
            if (key.Equals(x.key))
            {
                n--;
                return x.next;
            }
            x.next = delete(x.next, key); // recursion
            return x;
        }

        // iteraror
        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }


        public IEnumerator<Key> GetEnumerator()
        {
            var node = first;
            while (node != null)
            {
                yield return node.key;
                node = node.next;
            }
        }

        /**
   * Returns all keys in the symbol table as an {@code Iterable}.
   * To iterate over all of the keys in the symbol table named {@code st},
   * use the foreach notation: {@code for (Key key : st.keys())}.
   *
   * @return all keys in the symbol table
   */
        public IEnumerable<Key> keys()
        {
            Queue<Key> queue = new Queue<Key>();
            for (Node x = first; x != null; x = x.next)
                queue.Enqueue(x.key);
            return queue;
        }

        //
        public void ConsoleDisplay()
        {
            Console.WriteLine();
            Console.WriteLine("key" + " " + "val");
            for (Node n = first; n != null; n = n.next)
            {
                Console.WriteLine(" " + n.key + "  " + n.val);
            }
        }

    }
}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SymbolGraphExample

{

class SymbolTable

{

}

public class SequentialSearchST<Key, Value> : IEnumerable<Key> where Value:IComparable

{

private int n; // number of key-value pairs

private Node first; // the linked list of key-value pairs

// a helper linked list data type

private class Node

{

public Key key { get; set; }

public Value val { get; set; }

public Node next { get; set; }

public Node(Key key, Value val, Node next)

{

this.key = key;

this.val = val;

this.next = next;

}

/**

* Initializes an empty symbol table.

public SequentialSearchST()

{

}

/**

* Returns the number of key-value pairs in this symbol table.

* @return the number of key-value pairs in this symbol table

public int size()

{

return n;

}

/**

* Returns true if this symbol table is empty.

* @return {@code true} if this symbol table is empty;

* {@code false} otherwise

public bool isEmpty()

{

return size() == 0;

}

/**

* Returns true if this symbol table contains the specified key.

* @param key the key

* @return {@code true} if this symbol table contains {@code key};

* {@code false} otherwise

* @throws IllegalArgumentException if {@code key} is {@code null}

public bool contains(Key key)

{

if (key == null) throw new ArgumentException("argument to contains() is null");

Value r = get(key);

return (r.CompareTo(default(Value)) != 0);

}

/**

* Returns the value associated with the given key in this symbol table.

* @param key the key

* @return the value associated with the given key if the key is in the symbol table

* and {@code null} if the key is not in the symbol table

* @throws IllegalArgumentException if {@code key} is {@code null}

public Value get(Key key)

{

if (key == null) throw new ArgumentException("argument to get() is null");

for (Node x = first; x != null; x = x.next)

{

if (key.Equals(x.key))

return x.val;

}

return default(Value);

}

/**

* Inserts the specified key-value pair into the symbol table, overwriting the old

* value with the new value if the symbol table already contains the specified key.

* Deletes the specified key (and its associated value) from this symbol table

* if the specified value is {@code null}.

* @param key the key

* @param val the value

* @throws IllegalArgumentException if {@code key} is {@code null}

public void put(Key key, Value val)

{

if (key == null) throw new ArgumentException("first argument to put() is null");

if (val == null)

{

delete(key);

return;

}

for (Node x = first; x != null; x = x.next)

{

if (key.Equals(x.key))

{

x.val = val;

return;

}

first = new Node(key, val, first);

n++;

}

/**

* Removes the specified key and its associated value from this symbol table

* (if the key is in this symbol table).

* @param key the key

* @throws IllegalArgumentException if {@code key} is {@code null}

public void delete(Key key)

{

if (key == null) throw new ArgumentException("argument to delete() is null");

first = delete(first, key);

}

// delete key in linked list beginning at Node x

// warning: function call stack too large if table is large

private Node delete(Node x, Key key)

{

if (x == null) return null;

if (key.Equals(x.key))

{

n--;

return x.next;

}

x.next = delete(x.next, key); // recursion

return x;

}

// iteraror

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

return GetEnumerator();

}

public IEnumerator<Key> GetEnumerator()

{

var node = first;

while (node != null)

{

yield return node.key;

node = node.next;

}

/**

* Returns all keys in the symbol table as an {@code Iterable}.

* To iterate over all of the keys in the symbol table named {@code st},

* use the foreach notation: {@code for (Key key : st.keys())}.

* @return all keys in the symbol table

public IEnumerable<Key> keys()

{

Queue<Key> queue = new Queue<Key>();

for (Node x = first; x != null; x = x.next)

queue.Enqueue(x.key);

return queue;

}

public void ConsoleDisplay()

{

Console.WriteLine();

Console.WriteLine("key" + " " + "val");

for (Node n = first; n != null; n = n.next)

{

Console.WriteLine(" " + n.key + " " + n.val);

}

Graph.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SymbolGraphExample
{
    public class Graph
    {
        // private static final String NEWLINE = System.getProperty("line.separator");

        public int V { get; set; }
        public int E { get; set; }
        public Bag<int>[] adj { get; set; }


        /**
         * Initializes an empty graph with {@code V} vertices and 0 edges.
         * param V the number of vertices
         *
         * @param  V number of vertices
         * @throws IllegalArgumentException if {@code V < 0}
         */
        public Graph(int V)
        {
            if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");
            this.V = V;
            this.E = 0;
            adj = new Bag<int>[V];
            for (int v = 0; v < V; v++)
            {
                adj[v] = new Bag<int>();
            }
        }


        /**  
   * Initializes a graph from the specified input stream.
   * The format is the number of vertices <em>V</em>,
   * followed by the number of edges <em>E</em>,
   * followed by <em>E</em> pairs of vertices, with each entry separated by whitespace.
   *
   * @param  in the input stream
   * @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range
   * @throws IllegalArgumentException if the number of vertices or edges is negative
   * @throws IllegalArgumentException if the input stream is in the wrong format
   */

        public Graph(string filepath)
        {
            try
            {
                using (StreamReader sr = new StreamReader(filepath))
                {
                    int i = 0;

                    while (sr.Peek() >= 0)
                    {
                        // reading number of verticles
                        if (i == 0)
                        {
                            V = Convert.ToInt32(sr.ReadLine());
                            adj = new Bag<int>[V];
                            for (int v = 0; v < V; v++)
                            {
                                adj[v] = new Bag<int>();
                            }
                            i++;
                        }
                        // reading number of edges
                        else
                            if (i == 1)
                        {
                            E = Convert.ToInt32(sr.ReadLine());
                            if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");
                            i++;
                        }
                        else
                        {
                            //  for (int j = 0; j < E; j++)
                            //   {
                            string s = sr.ReadLine();
                            Char delimiter = ' ';
                            String[] substrings = s.Split(delimiter);
                            int v = Convert.ToInt32(substrings[0]);
                            int w = Convert.ToInt32(substrings[1]);
                            validateVertex(v);
                            validateVertex(w);
                            addEdge(v, w);
                        }

                    }
                }
            }
            catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };



        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        public void validateVertex(int v)
        {
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }
        /**
 * Adds the undirected edge v-w to this graph.
 *
 * @param  v one vertex in the edge
 * @param  w the other vertex in the edge
 * @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}
 */
        public void addEdge(int v, int w)
        {
            validateVertex(v);
            validateVertex(w);
            E++;
            adj[v].push(w);
            adj[w].push(v);
        }
        /**
   * Returns the vertices adjacent to vertex {@code v}.
   *
   * @param  v the vertex
   * @return the vertices adjacent to vertex {@code v}, as an iterable
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public IEnumerable<int> adjVerticles(int v)
        {
            validateVertex(v);
            return adj[v];
        }
        /**
   * Returns the degree of vertex {@code v}.
   *
   * @param  v the vertex
   * @return the degree of vertex {@code v}
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public int degree(int v)
        {
            validateVertex(v);
            return adj[v].size();
        }
        /**
 * Returns a string representation of this graph.
 *
 * @return the number of vertices <em>V</em>, followed by the number of edges <em>E</em>,
 *         followed by the <em>V</em> adjacency lists
 */
        public String toString()
        {
            StringBuilder s = new StringBuilder();
            s.Append(V + " vertices, " + E + " edges " + "\n");
            for (int v = 0; v < V; v++)
            {
                s.Append(v + ": ");
                foreach (int w in adj[v])
                {
                    s.Append(w + " ");
                }
                s.Append("\n");
            }
            return s.ToString();
        }

    }
}

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using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SymbolGraphExample

{

public class Graph

{

// private static final String NEWLINE = System.getProperty("line.separator");

public int V { get; set; }

public int E { get; set; }

public Bag<int>[] adj { get; set; }

/**

* Initializes an empty graph with {@code V} vertices and 0 edges.

* param V the number of vertices

* @param V number of vertices

* @throws IllegalArgumentException if {@code V < 0}

public Graph(int V)

{

if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");

this.V = V;

this.E = 0;

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

/**

* Initializes a graph from the specified input stream.

* The format is the number of vertices V,

* followed by the number of edges E,

* followed by E pairs of vertices, with each entry separated by whitespace.

* @param in the input stream

* @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range

* @throws IllegalArgumentException if the number of vertices or edges is negative

* @throws IllegalArgumentException if the input stream is in the wrong format

public Graph(string filepath)

{

try

{

using (StreamReader sr = new StreamReader(filepath))

{

int i = 0;

while (sr.Peek() >= 0)

{

// reading number of verticles

if (i == 0)

{

V = Convert.ToInt32(sr.ReadLine());

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

i++;

}

// reading number of edges

else

if (i == 1)

{

E = Convert.ToInt32(sr.ReadLine());

if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");

i++;

}

else

{

// for (int j = 0; j < E; j++)

// {

string s = sr.ReadLine();

Char delimiter = ' ';

String[] substrings = s.Split(delimiter);

int v = Convert.ToInt32(substrings[0]);

int w = Convert.ToInt32(substrings[1]);

validateVertex(v);

validateVertex(w);

addEdge(v, w);

}

catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

public void validateVertex(int v)

{

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

/**

* Adds the undirected edge v-w to this graph.

* @param v one vertex in the edge

* @param w the other vertex in the edge

* @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}

public void addEdge(int v, int w)

{

validateVertex(v);

validateVertex(w);

E++;

adj[v].push(w);

adj[w].push(v);

}

/**

* Returns the vertices adjacent to vertex {@code v}.

* @param v the vertex

* @return the vertices adjacent to vertex {@code v}, as an iterable

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public IEnumerable<int> adjVerticles(int v)

{

validateVertex(v);

return adj[v];

}

/**

* Returns the degree of vertex {@code v}.

* @param v the vertex

* @return the degree of vertex {@code v}

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int degree(int v)

{

validateVertex(v);

return adj[v].size();

}

/**

* Returns a string representation of this graph.

* @return the number of vertices V, followed by the number of edges E,

* followed by the V adjacency lists

public String toString()

{

StringBuilder s = new StringBuilder();

s.Append(V + " vertices, " + E + " edges " + "\n");

for (int v = 0; v < V; v++)

{

s.Append(v + ": ");

foreach (int w in adj[v])

{

s.Append(w + " ");

}

s.Append("\n");

}

return s.ToString();

}

Bag.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SymbolGraphExample
{
    public class Bag<T> : IEnumerable<T>
    {

        Node<T> first;
        private int N;
        class Node<T>
        {
            public T item;
            public Node<T> next;
        }

        public bool isEmpty() { return (first == null) || (N == 0); }
        public int size() { return N; }
        public void push(T item)
        {
            // adding to the begining
            Node<T> oldfirst = first;
            first = new Node<T>();
            first.item = item;
            first.next = oldfirst;
            N++;
        }

        /* // no pop in stack method
        public T pop()
        {
            T item = first.item;
            first = first.next;
            N--;
            return item;
        }
        */

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        public IEnumerator<T> GetEnumerator()
        {
            var node = first;
            while (node != null)
            {
                yield return node.item;
                node = node.next;
            }
        }

    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SymbolGraphExample

{

public class Bag<T> : IEnumerable<T>

{

Node<T> first;

private int N;

class Node<T>

{

public T item;

public Node<T> next;

}

public bool isEmpty() { return (first == null) || (N == 0); }

public int size() { return N; }

public void push(T item)

{

// adding to the begining

Node<T> oldfirst = first;

first = new Node<T>();

first.item = item;

first.next = oldfirst;

N++;

}

/* // no pop in stack method

public T pop()

{

T item = first.item;

first = first.next;

N--;

return item;

}

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

return GetEnumerator();

}

public IEnumerator<T> GetEnumerator()

{

var node = first;

while (node != null)

{

yield return node.item;

node = node.next;

}

Test

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SymbolGraphExample
{
    class Program
    {
        static void Main(string[] args)
        {
            SymbolGraph sg = new SymbolGraph("Airports.txt", ' ');
            Console.WriteLine(sg.toString());
            Console.ReadLine();
        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SymbolGraphExample

{

class Program

{

static void Main(string[] args)

{

SymbolGraph sg = new SymbolGraph("Airports.txt", ' ');

Console.WriteLine(sg.toString());

Console.ReadLine();

}

Posted in C# | Comments Off

C#. Algo.Graph. ClosableVertexSearch

Posted on 02.10.2017 by Stanislav_Panteleev

testGraph – which verticles are closable? We have 3 groups! 7 and 8 closable ! 0 and 7 not ! Git

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{
    public class CC // ClosableComponents
    {
        public bool[] marked;   // marked[v] = has vertex v been marked?
        public int[] id;           // id[v] = id of connected component containing v
        public int[] size;         // size[id] = number of vertices in given component
        public int count;          // number of connected components

        /**
         * Computes the connected components of the undirected graph {@code G}.
         *
         * @param G the undirected graph
         */
        public CC(Graph G)
        {
            marked = new bool[G.V];
            id = new int[G.V];
            size = new int[G.V];
            for (int v = 0; v < G.V; v++)
            {
                if (!marked[v])
                {
                    dfs(G, v);
                    count++;
                }
            }
        }
        
        // depth-first search for a Graph
        private void dfs(Graph G, int v)
        {
            marked[v] = true;
            id[v] = count;
            size[count]++;
            foreach (int w in G.adjVerticles(v))
            {
                if (!marked[w])
                {
                    dfs(G, w);
                }
            }
        }

        /**
 * Returns the component id of the connected component containing vertex {@code v}.
 *
 * @param  v the vertex
 * @return the component id of the connected component containing vertex {@code v}
 * @throws IllegalArgumentException unless {@code 0 <= v < V}
 */
        public int idGroup(int v)
        {
            validateVertex(v);
            return id[v];
        }
        /**
   * Returns the number of vertices in the connected component containing vertex {@code v}.
   *
   * @param  v the vertex
   * @return the number of vertices in the connected component containing vertex {@code v}
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public int sizeGroup(int v)
        {
            validateVertex(v);
            return size[id[v]];
        }
        /**
 * Returns the number of connected components in the graph {@code G}.
 *
 * @return the number of connected components in the graph {@code G}
 */
        public int countGroup()
        {
            return count;
        }
        /**
    * Returns true if vertices {@code v} and {@code w} are in the same
    * connected component.
    *
    * @param  v one vertex
    * @param  w the other vertex
    * @return {@code true} if vertices {@code v} and {@code w} are in the same
    *         connected component; {@code false} otherwise
    * @throws IllegalArgumentException unless {@code 0 <= v < V}
    * @throws IllegalArgumentException unless {@code 0 <= w < V}
    */
        public bool connected(int v, int w)
        {
            validateVertex(v);
            validateVertex(w);
            return idGroup(v) == idGroup(w);
        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        private void validateVertex(int v)
        {
            int V = marked.Length;
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }
    }
}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

public class CC // ClosableComponents

{

public bool[] marked; // marked[v] = has vertex v been marked?

public int[] id; // id[v] = id of connected component containing v

public int[] size; // size[id] = number of vertices in given component

public int count; // number of connected components

/**

* Computes the connected components of the undirected graph {@code G}.

* @param G the undirected graph

public CC(Graph G)

{

marked = new bool[G.V];

id = new int[G.V];

size = new int[G.V];

for (int v = 0; v < G.V; v++)

{

if (!marked[v])

{

dfs(G, v);

count++;

}

// depth-first search for a Graph

private void dfs(Graph G, int v)

{

marked[v] = true;

id[v] = count;

size[count]++;

foreach (int w in G.adjVerticles(v))

{

if (!marked[w])

{

dfs(G, w);

}

/**

* Returns the component id of the connected component containing vertex {@code v}.

* @param v the vertex

* @return the component id of the connected component containing vertex {@code v}

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int idGroup(int v)

{

validateVertex(v);

return id[v];

}

/**

* Returns the number of vertices in the connected component containing vertex {@code v}.

* @param v the vertex

* @return the number of vertices in the connected component containing vertex {@code v}

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int sizeGroup(int v)

{

validateVertex(v);

return size[id[v]];

}

/**

* Returns the number of connected components in the graph {@code G}.

* @return the number of connected components in the graph {@code G}

public int countGroup()

{

return count;

}

/**

* Returns true if vertices {@code v} and {@code w} are in the same

* connected component.

* @param v one vertex

* @param w the other vertex

* @return {@code true} if vertices {@code v} and {@code w} are in the same

* connected component; {@code false} otherwise

* @throws IllegalArgumentException unless {@code 0 <= v < V}

* @throws IllegalArgumentException unless {@code 0 <= w < V}

public bool connected(int v, int w)

{

validateVertex(v);

validateVertex(w);

return idGroup(v) == idGroup(w);

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

private void validateVertex(int v)

{

int V = marked.Length;

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

Graph.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Collections;
    using System.IO;


    public class Graph
    {
        // private static final String NEWLINE = System.getProperty("line.separator");

        public int V { get; set; }
        public int E { get; set; }
        public Bag<int>[] adj { get; set; }


        /**
         * Initializes an empty graph with {@code V} vertices and 0 edges.
         * param V the number of vertices
         *
         * @param  V number of vertices
         * @throws IllegalArgumentException if {@code V < 0}
         */
        public Graph(int V)
        {
            if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");
            this.V = V;
            this.E = 0;
            adj = new Bag<int>[V];
            for (int v = 0; v < V; v++)
            {
                adj[v] = new Bag<int>();
            }
        }


        /**  
   * Initializes a graph from the specified input stream.
   * The format is the number of vertices <em>V</em>,
   * followed by the number of edges <em>E</em>,
   * followed by <em>E</em> pairs of vertices, with each entry separated by whitespace.
   *
   * @param  in the input stream
   * @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range
   * @throws IllegalArgumentException if the number of vertices or edges is negative
   * @throws IllegalArgumentException if the input stream is in the wrong format
   */

        public Graph(string filepath)
        {
            try
            {
                using (StreamReader sr = new StreamReader(filepath))
                {
                    int i = 0;

                    while (sr.Peek() >= 0)
                    {
                        // reading number of verticles
                        if (i == 0)
                        {
                            V = Convert.ToInt32(sr.ReadLine());
                            adj = new Bag<int>[V];
                            for (int v = 0; v < V; v++)
                            {
                                adj[v] = new Bag<int>();
                            }
                            i++;
                        }
                        // reading number of edges
                        else
                            if (i == 1)
                        {
                            E = Convert.ToInt32(sr.ReadLine());
                            if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");
                            i++;
                        }
                        else
                        {
                            //  for (int j = 0; j < E; j++)
                            //   {
                            string s = sr.ReadLine();
                            Char delimiter = ' ';
                            String[] substrings = s.Split(delimiter);
                            int v = Convert.ToInt32(substrings[0]);
                            int w = Convert.ToInt32(substrings[1]);
                            validateVertex(v);
                            validateVertex(w);
                            addEdge(v, w);
                        }

                    }
                }
            }
            catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };



        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        public void validateVertex(int v)
        {
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }
        /**
 * Adds the undirected edge v-w to this graph.
 *
 * @param  v one vertex in the edge
 * @param  w the other vertex in the edge
 * @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}
 */
        public void addEdge(int v, int w)
        {
            validateVertex(v);
            validateVertex(w);
            E++;
            adj[v].push(w);
            adj[w].push(v);
        }
        /**
   * Returns the vertices adjacent to vertex {@code v}.
   *
   * @param  v the vertex
   * @return the vertices adjacent to vertex {@code v}, as an iterable
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public IEnumerable<int> adjVerticles(int v)
        {
            validateVertex(v);
            return adj[v];
        }
        /**
   * Returns the degree of vertex {@code v}.
   *
   * @param  v the vertex
   * @return the degree of vertex {@code v}
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public int degree(int v)
        {
            validateVertex(v);
            return adj[v].size();
        }
        /**
 * Returns a string representation of this graph.
 *
 * @return the number of vertices <em>V</em>, followed by the number of edges <em>E</em>,
 *         followed by the <em>V</em> adjacency lists
 */
        public String toString()
        {
            StringBuilder s = new StringBuilder();
            s.Append(V + " vertices, " + E + " edges " + "\n");
            for (int v = 0; v < V; v++)
            {
                s.Append(v + ": ");
                foreach (int w in adj[v])
                {
                    s.Append(w + " ");
                }
                s.Append("\n");
            }
            return s.ToString();
        }

    }


}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Collections;

using System.IO;

public class Graph

{

// private static final String NEWLINE = System.getProperty("line.separator");

public int V { get; set; }

public int E { get; set; }

public Bag<int>[] adj { get; set; }

/**

* Initializes an empty graph with {@code V} vertices and 0 edges.

* param V the number of vertices

* @param V number of vertices

* @throws IllegalArgumentException if {@code V < 0}

public Graph(int V)

{

if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");

this.V = V;

this.E = 0;

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

/**

* Initializes a graph from the specified input stream.

* The format is the number of vertices V,

* followed by the number of edges E,

* followed by E pairs of vertices, with each entry separated by whitespace.

* @param in the input stream

* @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range

* @throws IllegalArgumentException if the number of vertices or edges is negative

* @throws IllegalArgumentException if the input stream is in the wrong format

public Graph(string filepath)

{

try

{

using (StreamReader sr = new StreamReader(filepath))

{

int i = 0;

while (sr.Peek() >= 0)

{

// reading number of verticles

if (i == 0)

{

V = Convert.ToInt32(sr.ReadLine());

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

i++;

}

// reading number of edges

else

if (i == 1)

{

E = Convert.ToInt32(sr.ReadLine());

if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");

i++;

}

else

{

// for (int j = 0; j < E; j++)

// {

string s = sr.ReadLine();

Char delimiter = ' ';

String[] substrings = s.Split(delimiter);

int v = Convert.ToInt32(substrings[0]);

int w = Convert.ToInt32(substrings[1]);

validateVertex(v);

validateVertex(w);

addEdge(v, w);

}

catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

public void validateVertex(int v)

{

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

/**

* Adds the undirected edge v-w to this graph.

* @param v one vertex in the edge

* @param w the other vertex in the edge

* @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}

public void addEdge(int v, int w)

{

validateVertex(v);

validateVertex(w);

E++;

adj[v].push(w);

adj[w].push(v);

}

/**

* Returns the vertices adjacent to vertex {@code v}.

* @param v the vertex

* @return the vertices adjacent to vertex {@code v}, as an iterable

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public IEnumerable<int> adjVerticles(int v)

{

validateVertex(v);

return adj[v];

}

/**

* Returns the degree of vertex {@code v}.

* @param v the vertex

* @return the degree of vertex {@code v}

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int degree(int v)

{

validateVertex(v);

return adj[v].size();

}

/**

* Returns a string representation of this graph.

* @return the number of vertices V, followed by the number of edges E,

* followed by the V adjacency lists

public String toString()

{

StringBuilder s = new StringBuilder();

s.Append(V + " vertices, " + E + " edges " + "\n");

for (int v = 0; v < V; v++)

{

s.Append(v + ": ");

foreach (int w in adj[v])

{

s.Append(w + " ");

}

s.Append("\n");

}

return s.ToString();

}

Bag.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{

    public class Bag<T> : IEnumerable<T>
    {

        Node<T> first;
        private int N;
        class Node<T>
        {
            public T item;
            public Node<T> next;
        }

        public bool isEmpty() { return (first == null) || (N == 0); }
        public int size() { return N; }
        public void push(T item)
        {
            // adding to the begining
            Node<T> oldfirst = first;
            first = new Node<T>();
            first.item = item;
            first.next = oldfirst;
            N++;
        }

        /* // no pop in stack method
        public T pop()
        {
            T item = first.item;
            first = first.next;
            N--;
            return item;
        }
        */

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        public IEnumerator<T> GetEnumerator()
        {
            var node = first;
            while (node != null)
            {
                yield return node.item;
                node = node.next;
            }
        }

    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

public class Bag<T> : IEnumerable<T>

{

Node<T> first;

private int N;

class Node<T>

{

public T item;

public Node<T> next;

}

public bool isEmpty() { return (first == null) || (N == 0); }

public int size() { return N; }

public void push(T item)

{

// adding to the begining

Node<T> oldfirst = first;

first = new Node<T>();

first.item = item;

first.next = oldfirst;

N++;

}

/* // no pop in stack method

public T pop()

{

T item = first.item;

first = first.next;

N--;

return item;

}

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

return GetEnumerator();

}

public IEnumerator<T> GetEnumerator()

{

var node = first;

while (node != null)

{

yield return node.item;

node = node.next;

}

Test.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{
    class Program
    {
        static void Main(string[] args)
        {
            Graph g = new Graph("tinyG.txt");
            Console.WriteLine(g.toString());
            //testDFS(g);
            //testBFS(g);
            CCTest(g);


            Console.ReadLine();

        }

        static void CCTest(Graph g) // Closable components test
        {
            CC cc = new CC(g);
            Console.WriteLine();
            if (cc.connected(7, 8)) Console.WriteLine("Yes! 7 and 8 in one part of Graph, connected");
            if (!cc.connected(7, 0)) Console.WriteLine("N0! 7 and 0 in diff parts of Graph, not connected");
        }

        static void testBFS(Graph g)
        {
            BreadthFirstSearch bfp = new BreadthFirstSearch(g);
            // graph consists of 3 parts so we start search since 3 start elements
            bfp.bfs(g, 0);
            Console.WriteLine();
            bfp.bfs(g, 7);
            Console.WriteLine();
            bfp.bfs(g, 9);
        }

        static void testDFS(Graph g)
        {
            
            Console.WriteLine("Which verticles are marked?");
            DepthFirstSearch dfs = new DepthFirstSearch(g);

            // graph consists of 3 parts so we start search since 3 start elements
            dfs.dfs(g, 0);
            
            Console.WriteLine();
            dfs.dfs(g, 7); // will write to console if verticle marked
            Console.WriteLine();
            
            dfs.dfs(g, 9); // will write to console if verticle marked
            Console.WriteLine();

            dfs.unmarkAll();
            Console.WriteLine("Is verticle 12 in graph?");
            if (dfs.isVertex(g, 9, 12)) Console.WriteLine("Yes"); else Console.WriteLine("No");
            Console.Read();
        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

class Program

{

static void Main(string[] args)

{

Graph g = new Graph("tinyG.txt");

Console.WriteLine(g.toString());

//testDFS(g);

//testBFS(g);

CCTest(g);

Console.ReadLine();

}

static void CCTest(Graph g) // Closable components test

{

CC cc = new CC(g);

Console.WriteLine();

if (cc.connected(7, 8)) Console.WriteLine("Yes! 7 and 8 in one part of Graph, connected");

if (!cc.connected(7, 0)) Console.WriteLine("N0! 7 and 0 in diff parts of Graph, not connected");

}

static void testBFS(Graph g)

{

BreadthFirstSearch bfp = new BreadthFirstSearch(g);

// graph consists of 3 parts so we start search since 3 start elements

bfp.bfs(g, 0);

Console.WriteLine();

bfp.bfs(g, 7);

Console.WriteLine();

bfp.bfs(g, 9);

}

static void testDFS(Graph g)

{

Console.WriteLine("Which verticles are marked?");

DepthFirstSearch dfs = new DepthFirstSearch(g);

// graph consists of 3 parts so we start search since 3 start elements

dfs.dfs(g, 0);

Console.WriteLine();

dfs.dfs(g, 7); // will write to console if verticle marked

Console.WriteLine();

dfs.dfs(g, 9); // will write to console if verticle marked

Console.WriteLine();

dfs.unmarkAll();

Console.WriteLine("Is verticle 12 in graph?");

if (dfs.isVertex(g, 9, 12)) Console.WriteLine("Yes"); else Console.WriteLine("No");

Console.Read();

}

Posted in C# | Comments Off

С#.Algo.Graph.BreathFindSearch

Posted on 02.10.2017 by Stanislav_Panteleev

testGraph Git

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{
    class BreadthFirstPaths
    {
        private static int INFINITY = int.MaxValue;
        private bool[] marked;  // marked[v] = is there an s-v path
        private int[] edgeTo;      // edgeTo[v] = previous edge on shortest s-v path
        private int[] distTo;      // distTo[v] = number of edges shortest s-v path

        /**
   * Computes the shortest path between the source vertex {@code s}
   * and every other vertex in the graph {@code G}.
   * @param G the graph
   * @param s the source vertex
   * @throws IllegalArgumentException unless {@code 0 <= s < V}
   */
        public BreadthFirstPaths(Graph G, int s)
        {
            marked = new bool[G.V];
            distTo = new int[G.V];
            edgeTo = new int[G.V];
            G.validateVertex(s);
            bfs(G, s);
            //assert check(G, s);
        }
        public BreadthFirstPaths(Graph G)
        {
            marked = new bool[G.V];
            distTo = new int[G.V];
            edgeTo = new int[G.V];            
        }


        // breadth-first search from a single source
        public void bfs(Graph G, int s)
        {
            Queue<int> q = new Queue<int>();
            for (int v = 0; v < G.V; v++)
                distTo[v] = INFINITY;
            distTo[s] = 0;
            marked[s] = true;
            Console.Write(s + " ");
            q.Enqueue(s);

            while (q.Count!=0)
            {
                int v = q.Dequeue();
                foreach (int w in G.adjVerticles(v))
                {
                    if (!marked[w])
                    {
                        edgeTo[w] = v;
                        distTo[w] = distTo[v] + 1;
                        marked[w] = true;
                        Console.Write(w+" ");
                        q.Enqueue(w);
                    }
                }
            }
        }
        /**
 * Is there a path between the source vertex {@code s} (or sources) and vertex {@code v}?
 * @param v the vertex
 * @return {@code true} if there is a path, and {@code false} otherwise
 * @throws IllegalArgumentException unless {@code 0 <= v < V}
 */
        public bool hasPathTo(int v)
        {
            validateVertex(v);
            return marked[v];
        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        private void validateVertex(int v)
        {
            int V = marked.Length;
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }
        /**
 * Returns the number of edges in a shortest path between the source vertex {@code s}
 * (or sources) and vertex {@code v}?
 * @param v the vertex
 * @return the number of edges in a shortest path
 * @throws IllegalArgumentException unless {@code 0 <= v < V}
 */
        public int distanceTo(int v)
        {
            validateVertex(v);
            return distTo[v];
        }

        /**
         * Returns a shortest path between the source vertex {@code s} (or sources)
         * and {@code v}, or {@code null} if no such path.
         * @param  v the vertex
         * @return the sequence of vertices on a shortest path, as an Iterable
         * @throws IllegalArgumentException unless {@code 0 <= v < V}
         */
        public IEnumerable<int> pathTo(int v)
        {
            validateVertex(v);
            if (!hasPathTo(v)) return null;
            Stack<int> path = new Stack<int>();
            int x;
            for (x = v; distTo[x] != 0; x = edgeTo[x])
                path.Push(x);
                path.Push(x); // adding start verticle here
            return path;
        }

        public IEnumerable<int> pathTo2(int v,int startVertex)
        {
            validateVertex(v);
            validateVertex(startVertex);
            if (!hasPathTo(v)) return null;
            Stack<int> path = new Stack<int>();
            int x;
            for (x = v; x!=startVertex; x = edgeTo[x])
                path.Push(x);
            path.Push(startVertex);
            return path;
        }

    }
}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

class BreadthFirstPaths

{

private static int INFINITY = int.MaxValue;

private bool[] marked; // marked[v] = is there an s-v path

private int[] edgeTo; // edgeTo[v] = previous edge on shortest s-v path

private int[] distTo; // distTo[v] = number of edges shortest s-v path

/**

* Computes the shortest path between the source vertex {@code s}

* and every other vertex in the graph {@code G}.

* @param G the graph

* @param s the source vertex

* @throws IllegalArgumentException unless {@code 0 <= s < V}

public BreadthFirstPaths(Graph G, int s)

{

marked = new bool[G.V];

distTo = new int[G.V];

edgeTo = new int[G.V];

G.validateVertex(s);

bfs(G, s);

//assert check(G, s);

}

public BreadthFirstPaths(Graph G)

{

marked = new bool[G.V];

distTo = new int[G.V];

edgeTo = new int[G.V];

}

// breadth-first search from a single source

public void bfs(Graph G, int s)

{

Queue<int> q = new Queue<int>();

for (int v = 0; v < G.V; v++)

distTo[v] = INFINITY;

distTo[s] = 0;

marked[s] = true;

Console.Write(s + " ");

q.Enqueue(s);

while (q.Count!=0)

{

int v = q.Dequeue();

foreach (int w in G.adjVerticles(v))

{

if (!marked[w])

{

edgeTo[w] = v;

distTo[w] = distTo[v] + 1;

marked[w] = true;

Console.Write(w+" ");

q.Enqueue(w);

}

/**

* Is there a path between the source vertex {@code s} (or sources) and vertex {@code v}?

* @param v the vertex

* @return {@code true} if there is a path, and {@code false} otherwise

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public bool hasPathTo(int v)

{

validateVertex(v);

return marked[v];

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

private void validateVertex(int v)

{

int V = marked.Length;

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

/**

* Returns the number of edges in a shortest path between the source vertex {@code s}

* (or sources) and vertex {@code v}?

* @param v the vertex

* @return the number of edges in a shortest path

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int distanceTo(int v)

{

validateVertex(v);

return distTo[v];

}

/**

* Returns a shortest path between the source vertex {@code s} (or sources)

* and {@code v}, or {@code null} if no such path.

* @param v the vertex

* @return the sequence of vertices on a shortest path, as an Iterable

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public IEnumerable<int> pathTo(int v)

{

validateVertex(v);

if (!hasPathTo(v)) return null;

Stack<int> path = new Stack<int>();

int x;

for (x = v; distTo[x] != 0; x = edgeTo[x])

path.Push(x);

path.Push(x); // adding start verticle here

return path;

}

public IEnumerable<int> pathTo2(int v,int startVertex)

{

validateVertex(v);

validateVertex(startVertex);

if (!hasPathTo(v)) return null;

Stack<int> path = new Stack<int>();

int x;

for (x = v; x!=startVertex; x = edgeTo[x])

path.Push(x);

path.Push(startVertex);

return path;

}

Graph.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Collections;
    using System.IO;


    public class Graph
    {
        // private static final String NEWLINE = System.getProperty("line.separator");

        public int V { get; set; }
        public int E { get; set; }
        public Bag<int>[] adj { get; set; }


        /**
         * Initializes an empty graph with {@code V} vertices and 0 edges.
         * param V the number of vertices
         *
         * @param  V number of vertices
         * @throws IllegalArgumentException if {@code V < 0}
         */
        public Graph(int V)
        {
            if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");
            this.V = V;
            this.E = 0;
            adj = new Bag<int>[V];
            for (int v = 0; v < V; v++)
            {
                adj[v] = new Bag<int>();
            }
        }


        /**  
   * Initializes a graph from the specified input stream.
   * The format is the number of vertices <em>V</em>,
   * followed by the number of edges <em>E</em>,
   * followed by <em>E</em> pairs of vertices, with each entry separated by whitespace.
   *
   * @param  in the input stream
   * @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range
   * @throws IllegalArgumentException if the number of vertices or edges is negative
   * @throws IllegalArgumentException if the input stream is in the wrong format
   */

        public Graph(string filepath)
        {
            try
            {
                using (StreamReader sr = new StreamReader(filepath))
                {
                    int i = 0;

                    while (sr.Peek() >= 0)
                    {
                        // reading number of verticles
                        if (i == 0)
                        {
                            V = Convert.ToInt32(sr.ReadLine());
                            adj = new Bag<int>[V];
                            for (int v = 0; v < V; v++)
                            {
                                adj[v] = new Bag<int>();
                            }
                            i++;
                        }
                        // reading number of edges
                        else
                            if (i == 1)
                        {
                            E = Convert.ToInt32(sr.ReadLine());
                            if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");
                            i++;
                        }
                        else
                        {
                            //  for (int j = 0; j < E; j++)
                            //   {
                            string s = sr.ReadLine();
                            Char delimiter = ' ';
                            String[] substrings = s.Split(delimiter);
                            int v = Convert.ToInt32(substrings[0]);
                            int w = Convert.ToInt32(substrings[1]);
                            validateVertex(v);
                            validateVertex(w);
                            addEdge(v, w);
                        }

                    }
                }
            }
            catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };



        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        public void validateVertex(int v)
        {
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }
        /**
 * Adds the undirected edge v-w to this graph.
 *
 * @param  v one vertex in the edge
 * @param  w the other vertex in the edge
 * @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}
 */
        public void addEdge(int v, int w)
        {
            validateVertex(v);
            validateVertex(w);
            E++;
            adj[v].push(w);
            adj[w].push(v);
        }
        /**
   * Returns the vertices adjacent to vertex {@code v}.
   *
   * @param  v the vertex
   * @return the vertices adjacent to vertex {@code v}, as an iterable
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public IEnumerable<int> adjVerticles(int v)
        {
            validateVertex(v);
            return adj[v];
        }
        /**
   * Returns the degree of vertex {@code v}.
   *
   * @param  v the vertex
   * @return the degree of vertex {@code v}
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public int degree(int v)
        {
            validateVertex(v);
            return adj[v].size();
        }
        /**
 * Returns a string representation of this graph.
 *
 * @return the number of vertices <em>V</em>, followed by the number of edges <em>E</em>,
 *         followed by the <em>V</em> adjacency lists
 */
        public String toString()
        {
            StringBuilder s = new StringBuilder();
            s.Append(V + " vertices, " + E + " edges " + "\n");
            for (int v = 0; v < V; v++)
            {
                s.Append(v + ": ");
                foreach (int w in adj[v])
                {
                    s.Append(w + " ");
                }
                s.Append("\n");
            }
            return s.ToString();
        }

    }


}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Collections;

using System.IO;

public class Graph

{

// private static final String NEWLINE = System.getProperty("line.separator");

public int V { get; set; }

public int E { get; set; }

public Bag<int>[] adj { get; set; }

/**

* Initializes an empty graph with {@code V} vertices and 0 edges.

* param V the number of vertices

* @param V number of vertices

* @throws IllegalArgumentException if {@code V < 0}

public Graph(int V)

{

if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");

this.V = V;

this.E = 0;

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

/**

* Initializes a graph from the specified input stream.

* The format is the number of vertices V,

* followed by the number of edges E,

* followed by E pairs of vertices, with each entry separated by whitespace.

* @param in the input stream

* @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range

* @throws IllegalArgumentException if the number of vertices or edges is negative

* @throws IllegalArgumentException if the input stream is in the wrong format

public Graph(string filepath)

{

try

{

using (StreamReader sr = new StreamReader(filepath))

{

int i = 0;

while (sr.Peek() >= 0)

{

// reading number of verticles

if (i == 0)

{

V = Convert.ToInt32(sr.ReadLine());

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

i++;

}

// reading number of edges

else

if (i == 1)

{

E = Convert.ToInt32(sr.ReadLine());

if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");

i++;

}

else

{

// for (int j = 0; j < E; j++)

// {

string s = sr.ReadLine();

Char delimiter = ' ';

String[] substrings = s.Split(delimiter);

int v = Convert.ToInt32(substrings[0]);

int w = Convert.ToInt32(substrings[1]);

validateVertex(v);

validateVertex(w);

addEdge(v, w);

}

catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

public void validateVertex(int v)

{

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

/**

* Adds the undirected edge v-w to this graph.

* @param v one vertex in the edge

* @param w the other vertex in the edge

* @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}

public void addEdge(int v, int w)

{

validateVertex(v);

validateVertex(w);

E++;

adj[v].push(w);

adj[w].push(v);

}

/**

* Returns the vertices adjacent to vertex {@code v}.

* @param v the vertex

* @return the vertices adjacent to vertex {@code v}, as an iterable

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public IEnumerable<int> adjVerticles(int v)

{

validateVertex(v);

return adj[v];

}

/**

* Returns the degree of vertex {@code v}.

* @param v the vertex

* @return the degree of vertex {@code v}

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int degree(int v)

{

validateVertex(v);

return adj[v].size();

}

/**

* Returns a string representation of this graph.

* @return the number of vertices V, followed by the number of edges E,

* followed by the V adjacency lists

public String toString()

{

StringBuilder s = new StringBuilder();

s.Append(V + " vertices, " + E + " edges " + "\n");

for (int v = 0; v < V; v++)

{

s.Append(v + ": ");

foreach (int w in adj[v])

{

s.Append(w + " ");

}

s.Append("\n");

}

return s.ToString();

}

Bag.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{

    public class Bag<T> : IEnumerable<T>
    {

        Node<T> first;
        private int N;
        class Node<T>
        {
            public T item;
            public Node<T> next;
        }

        public bool isEmpty() { return (first == null) || (N == 0); }
        public int size() { return N; }
        public void push(T item)
        {
            // adding to the begining
            Node<T> oldfirst = first;
            first = new Node<T>();
            first.item = item;
            first.next = oldfirst;
            N++;
        }

        /* // no pop in stack method
        public T pop()
        {
            T item = first.item;
            first = first.next;
            N--;
            return item;
        }
        */

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        public IEnumerator<T> GetEnumerator()
        {
            var node = first;
            while (node != null)
            {
                yield return node.item;
                node = node.next;
            }
        }

    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

public class Bag<T> : IEnumerable<T>

{

Node<T> first;

private int N;

class Node<T>

{

public T item;

public Node<T> next;

}

public bool isEmpty() { return (first == null) || (N == 0); }

public int size() { return N; }

public void push(T item)

{

// adding to the begining

Node<T> oldfirst = first;

first = new Node<T>();

first.item = item;

first.next = oldfirst;

N++;

}

/* // no pop in stack method

public T pop()

{

T item = first.item;

first = first.next;

N--;

return item;

}

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

return GetEnumerator();

}

public IEnumerator<T> GetEnumerator()

{

var node = first;

while (node != null)

{

yield return node.item;

node = node.next;

}

Test

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SearchInGraphExample
{
    class Program
    {
        static void Main(string[] args)
        {
            Graph g = new Graph("tinyG.txt");
            Console.WriteLine(g.toString());
            //testDFS(g);
            testBFS(g);
            Console.ReadLine();

        }

        static void testBFS(Graph g)
        {
            BreadthFirstPaths bfp = new BreadthFirstPaths(g);
            // graph consists of 3 parts so we start search since 3 start elements
            bfp.bfs(g, 0);
            Console.WriteLine();
            bfp.bfs(g, 7);
            Console.WriteLine();
            bfp.bfs(g, 9);
        }

        static void testDFS(Graph g)
        {
            
            Console.WriteLine("Which verticles are marked?");
            DepthFirstSearch dfs = new DepthFirstSearch(g);

            // graph consists of 3 parts so we start search since 3 start elements
            dfs.dfs(g, 0);
            
            Console.WriteLine();
            dfs.dfs(g, 7); // will write to console if verticle marked
            Console.WriteLine();
            
            dfs.dfs(g, 9); // will write to console if verticle marked
            Console.WriteLine();

            dfs.unmarkAll();
            Console.WriteLine("Is verticle 12 in graph?");
            if (dfs.isVertex(g, 9, 12)) Console.WriteLine("Yes"); else Console.WriteLine("No");
            Console.Read();
        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace SearchInGraphExample

{

class Program

{

static void Main(string[] args)

{

Graph g = new Graph("tinyG.txt");

Console.WriteLine(g.toString());

//testDFS(g);

testBFS(g);

Console.ReadLine();

}

static void testBFS(Graph g)

{

BreadthFirstPaths bfp = new BreadthFirstPaths(g);

// graph consists of 3 parts so we start search since 3 start elements

bfp.bfs(g, 0);

Console.WriteLine();

bfp.bfs(g, 7);

Console.WriteLine();

bfp.bfs(g, 9);

}

static void testDFS(Graph g)

{

Console.WriteLine("Which verticles are marked?");

DepthFirstSearch dfs = new DepthFirstSearch(g);

// graph consists of 3 parts so we start search since 3 start elements

dfs.dfs(g, 0);

Console.WriteLine();

dfs.dfs(g, 7); // will write to console if verticle marked

Console.WriteLine();

dfs.dfs(g, 9); // will write to console if verticle marked

Console.WriteLine();

dfs.unmarkAll();

Console.WriteLine("Is verticle 12 in graph?");

if (dfs.isVertex(g, 9, 12)) Console.WriteLine("Yes"); else Console.WriteLine("No");

Console.Read();

}

Posted in C# | Comments Off

С#.Algo.Graph.DepthFindSearch

Posted on 02.10.2017 by Stanislav_Panteleev

testGraph Git

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DepthFirstSearch
{

    public class DepthFirstSearch
    {
        private bool[] marked;    // marked[v] = is there an s-v path?
        private int count;           // number of vertices connected to s

        /**
         * Computes the vertices in graph {@code G} that are
         * connected to the source vertex {@code s}.
         * @param G the graph
         * @param s the source vertex
         * @throws IllegalArgumentException unless {@code 0 <= s < V}
         */
        public DepthFirstSearch(Graph G, int s)
        {
            marked = new bool[G.V];
            G.validateVertex(s);
            dfs(G, s);
        }
        public DepthFirstSearch(Graph G)
        {
            marked = new bool[G.V];
        }


        // depth first search from v
        public void dfs(Graph G, int v)
        {
            count++;
            marked[v] = true;
            Console.Write(v + " ");
            foreach (int w in G.adjVerticles(v))
            {
                if (!marked[w])
                {
                    dfs(G, w);
                }
            }
        }

        public void unmarkAll()
        {            
            for(int i=0; i<marked.Length;i++)
            {
                marked[i] = false;
            }
        }

        // is some Verticle is?
        public bool isVertex(Graph G, int v,int searchedVertex)
        {
            bool r = false;
            count++;
            marked[v] = true;
            if (searchedVertex == v)
            {
                r = true;
                return r;
            }
            else
            {
                foreach (int w in G.adjVerticles(v))
                {
                    if (!marked[w])
                    {
                       r=isVertex(G, w, searchedVertex);
                        return r;                        
                    }                    
                }
                return r;
            }
          
        }

    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace DepthFirstSearch

{

public class DepthFirstSearch

{

private bool[] marked; // marked[v] = is there an s-v path?

private int count; // number of vertices connected to s

/**

* Computes the vertices in graph {@code G} that are

* connected to the source vertex {@code s}.

* @param G the graph

* @param s the source vertex

* @throws IllegalArgumentException unless {@code 0 <= s < V}

public DepthFirstSearch(Graph G, int s)

{

marked = new bool[G.V];

G.validateVertex(s);

dfs(G, s);

}

public DepthFirstSearch(Graph G)

{

marked = new bool[G.V];

}

// depth first search from v

public void dfs(Graph G, int v)

{

count++;

marked[v] = true;

Console.Write(v + " ");

foreach (int w in G.adjVerticles(v))

{

if (!marked[w])

{

dfs(G, w);

}

public void unmarkAll()

{

for(int i=0; i<marked.Length;i++)

{

marked[i] = false;

}

// is some Verticle is?

public bool isVertex(Graph G, int v,int searchedVertex)

{

bool r = false;

count++;

marked[v] = true;

if (searchedVertex == v)

{

r = true;

return r;

}

else

{

foreach (int w in G.adjVerticles(v))

{

if (!marked[w])

{

r=isVertex(G, w, searchedVertex);

return r;

}

return r;

}

Graph.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DepthFirstSearch
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Collections;
    using System.IO;


    public class Graph
    {
        // private static final String NEWLINE = System.getProperty("line.separator");

        public int V { get; set; }
        public int E { get; set; }
        public Bag<int>[] adj { get; set; }


        /**
         * Initializes an empty graph with {@code V} vertices and 0 edges.
         * param V the number of vertices
         *
         * @param  V number of vertices
         * @throws IllegalArgumentException if {@code V < 0}
         */
        public Graph(int V)
        {
            if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");
            this.V = V;
            this.E = 0;
            adj = new Bag<int>[V];
            for (int v = 0; v < V; v++)
            {
                adj[v] = new Bag<int>();
            }
        }


        /**  
   * Initializes a graph from the specified input stream.
   * The format is the number of vertices <em>V</em>,
   * followed by the number of edges <em>E</em>,
   * followed by <em>E</em> pairs of vertices, with each entry separated by whitespace.
   *
   * @param  in the input stream
   * @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range
   * @throws IllegalArgumentException if the number of vertices or edges is negative
   * @throws IllegalArgumentException if the input stream is in the wrong format
   */

        public Graph(string filepath)
        {
            try
            {
                using (StreamReader sr = new StreamReader(filepath))
                {
                    int i = 0;

                    while (sr.Peek() >= 0)
                    {
                        // reading number of verticles
                        if (i == 0)
                        {
                            V = Convert.ToInt32(sr.ReadLine());
                            adj = new Bag<int>[V];
                            for (int v = 0; v < V; v++)
                            {
                                adj[v] = new Bag<int>();
                            }
                            i++;
                        }
                        // reading number of edges
                        else
                            if (i == 1)
                        {
                            E = Convert.ToInt32(sr.ReadLine());
                            if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");
                            i++;
                        }
                        else
                        {
                            //  for (int j = 0; j < E; j++)
                            //   {
                            string s = sr.ReadLine();
                            Char delimiter = ' ';
                            String[] substrings = s.Split(delimiter);
                            int v = Convert.ToInt32(substrings[0]);
                            int w = Convert.ToInt32(substrings[1]);
                            validateVertex(v);
                            validateVertex(w);
                            addEdge(v, w);
                        }

                    }
                }
            }
            catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };



        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        public void validateVertex(int v)
        {
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }
        /**
 * Adds the undirected edge v-w to this graph.
 *
 * @param  v one vertex in the edge
 * @param  w the other vertex in the edge
 * @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}
 */
        public void addEdge(int v, int w)
        {
            validateVertex(v);
            validateVertex(w);
            E++;
            adj[v].push(w);
            adj[w].push(v);
        }
        /**
   * Returns the vertices adjacent to vertex {@code v}.
   *
   * @param  v the vertex
   * @return the vertices adjacent to vertex {@code v}, as an iterable
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public IEnumerable<int> adjVerticles(int v)
        {
            validateVertex(v);
            return adj[v];
        }
        /**
   * Returns the degree of vertex {@code v}.
   *
   * @param  v the vertex
   * @return the degree of vertex {@code v}
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public int degree(int v)
        {
            validateVertex(v);
            return adj[v].size();
        }
        /**
 * Returns a string representation of this graph.
 *
 * @return the number of vertices <em>V</em>, followed by the number of edges <em>E</em>,
 *         followed by the <em>V</em> adjacency lists
 */
        public String toString()
        {
            StringBuilder s = new StringBuilder();
            s.Append(V + " vertices, " + E + " edges " + "\n");
            for (int v = 0; v < V; v++)
            {
                s.Append(v + ": ");
                foreach (int w in adj[v])
                {
                    s.Append(w + " ");
                }
                s.Append("\n");
            }
            return s.ToString();
        }

    }


}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace DepthFirstSearch

{

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Collections;

using System.IO;

public class Graph

{

// private static final String NEWLINE = System.getProperty("line.separator");

public int V { get; set; }

public int E { get; set; }

public Bag<int>[] adj { get; set; }

/**

* Initializes an empty graph with {@code V} vertices and 0 edges.

* param V the number of vertices

* @param V number of vertices

* @throws IllegalArgumentException if {@code V < 0}

public Graph(int V)

{

if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");

this.V = V;

this.E = 0;

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

/**

* Initializes a graph from the specified input stream.

* The format is the number of vertices V,

* followed by the number of edges E,

* followed by E pairs of vertices, with each entry separated by whitespace.

* @param in the input stream

* @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range

* @throws IllegalArgumentException if the number of vertices or edges is negative

* @throws IllegalArgumentException if the input stream is in the wrong format

public Graph(string filepath)

{

try

{

using (StreamReader sr = new StreamReader(filepath))

{

int i = 0;

while (sr.Peek() >= 0)

{

// reading number of verticles

if (i == 0)

{

V = Convert.ToInt32(sr.ReadLine());

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

i++;

}

// reading number of edges

else

if (i == 1)

{

E = Convert.ToInt32(sr.ReadLine());

if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");

i++;

}

else

{

// for (int j = 0; j < E; j++)

// {

string s = sr.ReadLine();

Char delimiter = ' ';

String[] substrings = s.Split(delimiter);

int v = Convert.ToInt32(substrings[0]);

int w = Convert.ToInt32(substrings[1]);

validateVertex(v);

validateVertex(w);

addEdge(v, w);

}

catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

public void validateVertex(int v)

{

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

/**

* Adds the undirected edge v-w to this graph.

* @param v one vertex in the edge

* @param w the other vertex in the edge

* @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}

public void addEdge(int v, int w)

{

validateVertex(v);

validateVertex(w);

E++;

adj[v].push(w);

adj[w].push(v);

}

/**

* Returns the vertices adjacent to vertex {@code v}.

* @param v the vertex

* @return the vertices adjacent to vertex {@code v}, as an iterable

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public IEnumerable<int> adjVerticles(int v)

{

validateVertex(v);

return adj[v];

}

/**

* Returns the degree of vertex {@code v}.

* @param v the vertex

* @return the degree of vertex {@code v}

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int degree(int v)

{

validateVertex(v);

return adj[v].size();

}

/**

* Returns a string representation of this graph.

* @return the number of vertices V, followed by the number of edges E,

* followed by the V adjacency lists

public String toString()

{

StringBuilder s = new StringBuilder();

s.Append(V + " vertices, " + E + " edges " + "\n");

for (int v = 0; v < V; v++)

{

s.Append(v + ": ");

foreach (int w in adj[v])

{

s.Append(w + " ");

}

s.Append("\n");

}

return s.ToString();

}

Bag.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DepthFirstSearch
{

    public class Bag<T> : IEnumerable<T>
    {

        Node<T> first;
        private int N;
        class Node<T>
        {
            public T item;
            public Node<T> next;
        }

        public bool isEmpty() { return (first == null) || (N == 0); }
        public int size() { return N; }
        public void push(T item)
        {
            // adding to the begining
            Node<T> oldfirst = first;
            first = new Node<T>();
            first.item = item;
            first.next = oldfirst;
            N++;
        }

        /* // no pop in stack method
        public T pop()
        {
            T item = first.item;
            first = first.next;
            N--;
            return item;
        }
        */

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        public IEnumerator<T> GetEnumerator()
        {
            var node = first;
            while (node != null)
            {
                yield return node.item;
                node = node.next;
            }
        }

    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace DepthFirstSearch

{

public class Bag<T> : IEnumerable<T>

{

Node<T> first;

private int N;

class Node<T>

{

public T item;

public Node<T> next;

}

public bool isEmpty() { return (first == null) || (N == 0); }

public int size() { return N; }

public void push(T item)

{

// adding to the begining

Node<T> oldfirst = first;

first = new Node<T>();

first.item = item;

first.next = oldfirst;

N++;

}

/* // no pop in stack method

public T pop()

{

T item = first.item;

first = first.next;

N--;

return item;

}

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

return GetEnumerator();

}

public IEnumerator<T> GetEnumerator()

{

var node = first;

while (node != null)

{

yield return node.item;

node = node.next;

}

Test.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DepthFirstSearch
{
    class Program
    {
        static void Main(string[] args)
        {
            Graph g = new Graph("tinyG.txt");
            
            Console.WriteLine(g.toString());
            Console.WriteLine("Which verticles are marked?");
            DepthFirstSearch dfs = new DepthFirstSearch(g);
            dfs.dfs(g,0);
            Console.WriteLine();
            dfs.dfs(g, 7);
            Console.WriteLine();
            dfs.dfs(g, 9);
            Console.WriteLine();
            dfs.unmarkAll();
            Console.WriteLine("Is verticle 12 in graph?");
            if (dfs.isVertex(g, 9, 12)) Console.WriteLine("Yes"); else Console.WriteLine("No");
            Console.Read();
        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace DepthFirstSearch

{

class Program

{

static void Main(string[] args)

{

Graph g = new Graph("tinyG.txt");

Console.WriteLine(g.toString());

Console.WriteLine("Which verticles are marked?");

DepthFirstSearch dfs = new DepthFirstSearch(g);

dfs.dfs(g,0);

Console.WriteLine();

dfs.dfs(g, 7);

Console.WriteLine();

dfs.dfs(g, 9);

Console.WriteLine();

dfs.unmarkAll();

Console.WriteLine("Is verticle 12 in graph?");

if (dfs.isVertex(g, 9, 12)) Console.WriteLine("Yes"); else Console.WriteLine("No");

Console.Read();

}

Posted in C# | Comments Off

С#. Graph on linked lists

Posted on 02.10.2017 by Stanislav_Panteleev

testGraph Git Graph can be initiated from fileName.txt first line number of verticles second line number of edges other lines adjacent lines fileName.txt

0 5

4 3

0 1

9 12

6 4

5 4

0 2

11 12

9 10

0 6

7 8

9 11

5 3

Graph.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Collections;
using System.IO;

namespace GraphExample
{
    public class Graph
    {
        // private static final String NEWLINE = System.getProperty("line.separator");

        public int V { get; set; }
        public int E { get; set; }
        private Bag<int>[] adj;


        /**
         * Initializes an empty graph with {@code V} vertices and 0 edges.
         * param V the number of vertices
         *
         * @param  V number of vertices
         * @throws IllegalArgumentException if {@code V < 0}
         */
        public Graph(int V)
        {
            if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");
            this.V = V;
            this.E = 0;
            adj = new Bag<int>[V];
            for (int v = 0; v < V; v++)
            {
                adj[v] = new Bag<int>();
            }
        }


        /**  
   * Initializes a graph from the specified input stream.
   * The format is the number of vertices <em>V</em>,
   * followed by the number of edges <em>E</em>,
   * followed by <em>E</em> pairs of vertices, with each entry separated by whitespace.
   *
   * @param  in the input stream
   * @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range
   * @throws IllegalArgumentException if the number of vertices or edges is negative
   * @throws IllegalArgumentException if the input stream is in the wrong format
   */

        public Graph(string filepath)
        {
            try
            {
                using (StreamReader sr = new StreamReader(filepath))
                {
                    int i = 0;
                    
                    while (sr.Peek() >= 0)
                    {
                        // reading number of verticles
                        if (i == 0)
                        {
                            V = Convert.ToInt32(sr.ReadLine());
                            adj = new Bag<int>[V];
                            for (int v = 0; v < V; v++)
                            {
                                adj[v] = new Bag<int>();
                            }
                            i++;
                        }
                        // reading number of edges
                        else
                            if (i == 1)
                        {
                            E = Convert.ToInt32(sr.ReadLine());
                            if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");
                            i++;
                        }
                        else
                        {
                            //  for (int j = 0; j < E; j++)
                            //   {
                            string s = sr.ReadLine();
                            Char delimiter = ' ';
                            String[] substrings = s.Split(delimiter);
                            int v = Convert.ToInt32(substrings[0]);
                            int w = Convert.ToInt32(substrings[1]);
                            validateVertex(v);
                            validateVertex(w);
                            addEdge(v, w);                            
                        }

                    }
                }
            }
            catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };



        }
        // throw an IllegalArgumentException unless {@code 0 <= v < V}
        private void validateVertex(int v)
        {
            if (v < 0 || v >= V)
                throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));
        }
        /**
 * Adds the undirected edge v-w to this graph.
 *
 * @param  v one vertex in the edge
 * @param  w the other vertex in the edge
 * @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}
 */
        public void addEdge(int v, int w)
        {
            validateVertex(v);
            validateVertex(w);
            E++;
            adj[v].push(w);
            adj[w].push(v);
        }
        /**
   * Returns the vertices adjacent to vertex {@code v}.
   *
   * @param  v the vertex
   * @return the vertices adjacent to vertex {@code v}, as an iterable
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public IEnumerable<int> adjVerticles(int v)
        {
            validateVertex(v);
            return adj[v];
        }
        /**
   * Returns the degree of vertex {@code v}.
   *
   * @param  v the vertex
   * @return the degree of vertex {@code v}
   * @throws IllegalArgumentException unless {@code 0 <= v < V}
   */
        public int degree(int v)
        {
            validateVertex(v);
            return adj[v].size();
        }
        /**
 * Returns a string representation of this graph.
 *
 * @return the number of vertices <em>V</em>, followed by the number of edges <em>E</em>,
 *         followed by the <em>V</em> adjacency lists
 */
        public String toString()
        {
            StringBuilder s = new StringBuilder();
            s.Append(V + " vertices, " + E + " edges " + "\n");
            for (int v = 0; v < V; v++)
            {
                s.Append(v + ": ");
                foreach (int w in adj[v])
                {
                    s.Append(w + " ");
                }
                s.Append("\n");
            }
            return s.ToString();
        }

    }


}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Collections;

using System.IO;

namespace GraphExample

{

public class Graph

{

// private static final String NEWLINE = System.getProperty("line.separator");

public int V { get; set; }

public int E { get; set; }

private Bag<int>[] adj;

/**

* Initializes an empty graph with {@code V} vertices and 0 edges.

* param V the number of vertices

* @param V number of vertices

* @throws IllegalArgumentException if {@code V < 0}

public Graph(int V)

{

if (V < 0) throw new ArgumentException("Number of vertices must be nonnegative");

this.V = V;

this.E = 0;

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

/**

* Initializes a graph from the specified input stream.

* The format is the number of vertices V,

* followed by the number of edges E,

* followed by E pairs of vertices, with each entry separated by whitespace.

* @param in the input stream

* @throws IllegalArgumentException if the endpoints of any edge are not in prescribed range

* @throws IllegalArgumentException if the number of vertices or edges is negative

* @throws IllegalArgumentException if the input stream is in the wrong format

public Graph(string filepath)

{

try

{

using (StreamReader sr = new StreamReader(filepath))

{

int i = 0;

while (sr.Peek() >= 0)

{

// reading number of verticles

if (i == 0)

{

V = Convert.ToInt32(sr.ReadLine());

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

i++;

}

// reading number of edges

else

if (i == 1)

{

E = Convert.ToInt32(sr.ReadLine());

if (E < 0) throw new ArgumentException("number of edges in a Graph must be nonnegative");

i++;

}

else

{

// for (int j = 0; j < E; j++)

// {

string s = sr.ReadLine();

Char delimiter = ' ';

String[] substrings = s.Split(delimiter);

int v = Convert.ToInt32(substrings[0]);

int w = Convert.ToInt32(substrings[1]);

validateVertex(v);

validateVertex(w);

addEdge(v, w);

}

catch (Exception e) { Console.WriteLine("The process failed: {0}", e.ToString()); };

}

// throw an IllegalArgumentException unless {@code 0 <= v < V}

private void validateVertex(int v)

{

if (v < 0 || v >= V)

throw new ArgumentException("vertex " + v + " is not between 0 and " + (V - 1));

}

/**

* Adds the undirected edge v-w to this graph.

* @param v one vertex in the edge

* @param w the other vertex in the edge

* @throws IllegalArgumentException unless both {@code 0 <= v < V} and {@code 0 <= w < V}

public void addEdge(int v, int w)

{

validateVertex(v);

validateVertex(w);

E++;

adj[v].push(w);

adj[w].push(v);

}

/**

* Returns the vertices adjacent to vertex {@code v}.

* @param v the vertex

* @return the vertices adjacent to vertex {@code v}, as an iterable

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public IEnumerable<int> adjVerticles(int v)

{

validateVertex(v);

return adj[v];

}

/**

* Returns the degree of vertex {@code v}.

* @param v the vertex

* @return the degree of vertex {@code v}

* @throws IllegalArgumentException unless {@code 0 <= v < V}

public int degree(int v)

{

validateVertex(v);

return adj[v].size();

}

/**

* Returns a string representation of this graph.

* @return the number of vertices V, followed by the number of edges E,

* followed by the V adjacency lists

public String toString()

{

StringBuilder s = new StringBuilder();

s.Append(V + " vertices, " + E + " edges " + "\n");

for (int v = 0; v < V; v++)

{

s.Append(v + ": ");

foreach (int w in adj[v])

{

s.Append(w + " ");

}

s.Append("\n");

}

return s.ToString();

}

Example of use

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace GraphExample
{
    class Program
    {
        static void Main(string[] args)
        {
            Graph g = new Graph("123.txt");
            Console.WriteLine(g.toString());
            Console.Read();
        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace GraphExample

{

class Program

{

static void Main(string[] args)

{

Graph g = new Graph("123.txt");

Console.WriteLine(g.toString());

Console.Read();

}

Posted in C# | Comments Off

C#. LinearProbingHashST

Posted on 30.09.2017 by Stanislav_Panteleev

Seidgwick Git LinearProbingHashST.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LinearProbingHashST
{
    class LinearProbingHashST<Key,Value>
    {
        private int INIT_CAPACITY = 4;

        public int n;           // number of key-value pairs in the symbol table
        public int m;           // size of linear probing table
        public Key[] keys;      // the keys
        public Value[] vals;    // the values
                                 
        /**
         * Initializes an empty symbol table.
        */
        public LinearProbingHashST()
        {            
            m = INIT_CAPACITY;
            n = 0;
            keys = new Key[m];
            vals = new Value[m];
        }

        /**
         * Initializes an empty symbol table with the specified initial capacity.
         *
         * @param capacity the initial capacity
         */
        public LinearProbingHashST(int capacity)  
        {
            m = capacity;
            n = 0;
            keys = new Key[m]; 
            vals = new Value[m];
        }
        /**
     * Returns the number of key-value pairs in this symbol table.
     *
     * @return the number of key-value pairs in this symbol table
     */
        public int size()
        {
            return n;
        }

        /**
         * Returns true if this symbol table is empty.
         *
         * @return {@code true} if this symbol table is empty;
         *         {@code false} otherwise
         */
        public bool isEmpty()
        {
            return size() == 0;
        }

        /**
         * Returns true if this symbol table contains the specified key.
         *
         * @param  key the key
         * @return {@code true} if this symbol table contains {@code key};
         *         {@code false} otherwise
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public bool contains(Key key)
        {
            if (key == null) throw new ArgumentException("argument to contains() is null");
            return get(key) != null;
        }

        // hash function for keys - returns value between 0 and M-1
        private int hash(Key key)
        {
            return (key.GetHashCode() & 0x7fffffff) % m;
        }
        // resizes the hash table to the given capacity by re-hashing all of the keys
        private void resize(int capacity)
        {
            LinearProbingHashST<Key, Value> temp = new LinearProbingHashST<Key, Value>(capacity);
            for (int i = 0; i < m; i++)
            {
                if (keys[i] != null)
                {
                    temp.put(keys[i], vals[i]);
                }
            }
            keys = temp.keys;
            vals = temp.vals;
            m = temp.m;
        }
        /**
     * Inserts the specified key-value pair into the symbol table, overwriting the old 
     * value with the new value if the symbol table already contains the specified key.
     * Deletes the specified key (and its associated value) from this symbol table
     * if the specified value is {@code null}.
     *
     * @param  key the key
     * @param  val the value
     * @throws IllegalArgumentException if {@code key} is {@code null}
     */
        public void put(Key key, Value val)
        {
            if (key == null) throw new ArgumentException("first argument to put() is null");

            if (val == null)
            {
                delete(key);
                return;
            }

            // double table size if 50% full
            if (n >= m / 2) resize(2 * m);

            int i;
            for (i = hash(key); keys[i] != null; i = (i + 1) % m)
            {
                if (keys[i].Equals(key))
                {
                    vals[i] = val;
                    return;
                }
            }
            keys[i] = key;
            vals[i] = val;
            n++;
        }
        /**
    * Returns the value associated with the specified key.
    * @param key the key
    * @return the value associated with {@code key};
    *         {@code null} if no such value
    * @throws IllegalArgumentException if {@code key} is {@code null}
    */
        public Value get(Key key)
        {
            if (key == null) throw new ArgumentException("argument to get() is null");
            for (int i = hash(key); keys[i] != null; i = (i + 1) % m)
                if (keys[i].Equals(key))
                    return vals[i];
            return default(Value);
        }
        /**
    * Removes the specified key and its associated value from this symbol table     
    * (if the key is in this symbol table).    
    *
    * @param  key the key
    * @throws IllegalArgumentException if {@code key} is {@code null}
    */
        public void delete(Key key)
        {
            if (key == null) throw new ArgumentException("argument to delete() is null");
            if (!contains(key)) return;

            // find position i of key
            int i = hash(key);
            while (!key.Equals(keys[i]))
            {
                i = (i + 1) % m;
            }

            // delete key and associated value
            keys[i] = default(Key);
            vals[i] = default(Value);

            // rehash all keys in same cluster
            i = (i + 1) % m;
            while (keys[i] != null)
            {
                // delete keys[i] an vals[i] and reinsert
                Key keyToRehash = keys[i];
                Value valToRehash = vals[i];
                keys[i] = default(Key);
                vals[i] = default(Value);
                n--;
                put(keyToRehash, valToRehash);
                i = (i + 1) % m;
            }

            n--;

            // halves size of array if it's 12.5% full or less
            if (n > 0 && n <= m / 8) resize(m / 2);

            Trace.Assert(check());
        }
        /**
     * Returns all keys in this symbol table as an {@code Iterable}.
     * To iterate over all of the keys in the symbol table named {@code st},
     * use the foreach notation: {@code for (Key key : st.keys())}.
     *
     * @return all keys in this symbol table
     */
        public IEnumerable<Key> allkeys()
        {
            Queue<Key> queue = new Queue<Key>();
            for (int i = 0; i < m; i++)
                if (keys[i] != null) queue.Enqueue(keys[i]);
            return queue;
        }

        public void ConsoleDisplay()
        {
            Console.WriteLine("key" + " " + "val");
            for (int i = 0; i < m; i++)
            {
                if (keys[i] != null)
                Console.WriteLine(" " + keys[i] + "  " + vals[i]);
            }
        }


        // integrity check - don't check after each put() because
        // integrity not maintained during a delete()
        private bool check()
        {

            // check that hash table is at most 50% full
            if (m < 2 * n)
            {
                Console.WriteLine("Hash table size m = " + m + "; array size n = " + n);
                return false;
            }

            // check that each key in table can be found by get()
            for (int i = 0; i < m; i++)
            {
                if (keys[i] == null) continue;
                else if (!get(keys[i]).Equals(vals[i]))
                {
                    Console.WriteLine("get[" + keys[i] + "] = " + get(keys[i]) + "; vals[i] = " + vals[i]);
                    return false;
                }
            }
            return true;
        }

    }
}

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using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace LinearProbingHashST

{

class LinearProbingHashST<Key,Value>

{

private int INIT_CAPACITY = 4;

public int n; // number of key-value pairs in the symbol table

public int m; // size of linear probing table

public Key[] keys; // the keys

public Value[] vals; // the values

/**

* Initializes an empty symbol table.

public LinearProbingHashST()

{

m = INIT_CAPACITY;

n = 0;

keys = new Key[m];

vals = new Value[m];

}

/**

* Initializes an empty symbol table with the specified initial capacity.

* @param capacity the initial capacity

public LinearProbingHashST(int capacity)

{

m = capacity;

n = 0;

keys = new Key[m];

vals = new Value[m];

}

/**

* Returns the number of key-value pairs in this symbol table.

* @return the number of key-value pairs in this symbol table

public int size()

{

return n;

}

/**

* Returns true if this symbol table is empty.

* @return {@code true} if this symbol table is empty;

* {@code false} otherwise

public bool isEmpty()

{

return size() == 0;

}

/**

* Returns true if this symbol table contains the specified key.

* @param key the key

* @return {@code true} if this symbol table contains {@code key};

* {@code false} otherwise

* @throws IllegalArgumentException if {@code key} is {@code null}

public bool contains(Key key)

{

if (key == null) throw new ArgumentException("argument to contains() is null");

return get(key) != null;

}

// hash function for keys - returns value between 0 and M-1

private int hash(Key key)

{

return (key.GetHashCode() & 0x7fffffff) % m;

}

// resizes the hash table to the given capacity by re-hashing all of the keys

private void resize(int capacity)

{

LinearProbingHashST<Key, Value> temp = new LinearProbingHashST<Key, Value>(capacity);

for (int i = 0; i < m; i++)

{

if (keys[i] != null)

{

temp.put(keys[i], vals[i]);

}

keys = temp.keys;

vals = temp.vals;

m = temp.m;

}

/**

* Inserts the specified key-value pair into the symbol table, overwriting the old

* value with the new value if the symbol table already contains the specified key.

* Deletes the specified key (and its associated value) from this symbol table

* if the specified value is {@code null}.

* @param key the key

* @param val the value

* @throws IllegalArgumentException if {@code key} is {@code null}

public void put(Key key, Value val)

{

if (key == null) throw new ArgumentException("first argument to put() is null");

if (val == null)

{

delete(key);

return;

}

// double table size if 50% full

if (n >= m / 2) resize(2 * m);

int i;

for (i = hash(key); keys[i] != null; i = (i + 1) % m)

{

if (keys[i].Equals(key))

{

vals[i] = val;

return;

}

keys[i] = key;

vals[i] = val;

n++;

}

/**

* Returns the value associated with the specified key.

* @param key the key

* @return the value associated with {@code key};

* {@code null} if no such value

* @throws IllegalArgumentException if {@code key} is {@code null}

public Value get(Key key)

{

if (key == null) throw new ArgumentException("argument to get() is null");

for (int i = hash(key); keys[i] != null; i = (i + 1) % m)

if (keys[i].Equals(key))

return vals[i];

return default(Value);

}

/**

* Removes the specified key and its associated value from this symbol table

* (if the key is in this symbol table).

* @param key the key

* @throws IllegalArgumentException if {@code key} is {@code null}

public void delete(Key key)

{

if (key == null) throw new ArgumentException("argument to delete() is null");

if (!contains(key)) return;

// find position i of key

int i = hash(key);

while (!key.Equals(keys[i]))

{

i = (i + 1) % m;

}

// delete key and associated value

keys[i] = default(Key);

vals[i] = default(Value);

// rehash all keys in same cluster

i = (i + 1) % m;

while (keys[i] != null)

{

// delete keys[i] an vals[i] and reinsert

Key keyToRehash = keys[i];

Value valToRehash = vals[i];

keys[i] = default(Key);

vals[i] = default(Value);

n--;

put(keyToRehash, valToRehash);

i = (i + 1) % m;

}

n--;

// halves size of array if it's 12.5% full or less

if (n > 0 && n <= m / 8) resize(m / 2);

Trace.Assert(check());

}

/**

* Returns all keys in this symbol table as an {@code Iterable}.

* To iterate over all of the keys in the symbol table named {@code st},

* use the foreach notation: {@code for (Key key : st.keys())}.

* @return all keys in this symbol table

public IEnumerable<Key> allkeys()

{

Queue<Key> queue = new Queue<Key>();

for (int i = 0; i < m; i++)

if (keys[i] != null) queue.Enqueue(keys[i]);

return queue;

}

public void ConsoleDisplay()

{

Console.WriteLine("key" + " " + "val");

for (int i = 0; i < m; i++)

{

if (keys[i] != null)

Console.WriteLine(" " + keys[i] + " " + vals[i]);

}

// integrity check - don't check after each put() because

// integrity not maintained during a delete()

private bool check()

{

// check that hash table is at most 50% full

if (m < 2 * n)

{

Console.WriteLine("Hash table size m = " + m + "; array size n = " + n);

return false;

}

// check that each key in table can be found by get()

for (int i = 0; i < m; i++)

{

if (keys[i] == null) continue;

else if (!get(keys[i]).Equals(vals[i]))

{

Console.WriteLine("get[" + keys[i] + "] = " + get(keys[i]) + "; vals[i] = " + vals[i]);

return false;

}

return true;

}

Git Test

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LinearProbingHashST
{
    class Program
    {
        static void Main(string[] args)
        {
            LinearProbingHashST<string, int> lp = new LinearProbingHashST<string, int>(16);
            string[] a =  {
                "S",
                "E",
                "A",
                "R",
                "C",
                "H",
                "E",
                "X",
                "A",
                "M",
                "P",
                "L",
                "E"
            };
           
            for (int i = 0; i < a.Length; i++)
            {
                lp.put(a[i], i);
            }
            lp.ConsoleDisplay();
            Console.ReadLine();
        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace LinearProbingHashST

{

class Program

{

static void Main(string[] args)

{

LinearProbingHashST<string, int> lp = new LinearProbingHashST<string, int>(16);

string[] a = {

"S",

"E",

"A",

"R",

"C",

"H",

"E",

"X",

"A",

"M",

"P",

"L",

"E"

};

for (int i = 0; i < a.Length; i++)

{

lp.put(a[i], i);

}

lp.ConsoleDisplay();

Console.ReadLine();

}

Posted in C# | Comments Off

C#. Algo. SeparateChainingHashST – hashing with separate chains

Posted on 30.09.2017 by Stanislav_Panteleev

We use here symbol table based on linked list (class SequentialSearchST<Key, Value>), and building such linked list for every hash, so we have array of linked lists Jasewick Git

Posted in C# | Comments Off

C#.Algo.RedBlackBST

Posted on 29.09.2017 by Stanislav_Panteleev

Git From Jasewick, Algos on Java, translated to C# Binary tree grows down, balanced binary tree (for ex. 2-3 BST or RedBlack BST is not so hi – so search in it will take only lgN) RedBlackBST.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RedBlackBSTExample
{
    class RedBlackBST<Key,Value>:IEnumerable where Key:IComparable
    {
        public bool RED   = true;
        public bool BLACK = false;

    private Node root;     // root of the BST

        // BST helper node data type
        private class Node
        {
            public Key key;           // key
            public Value val;         // associated data
            public Node left, right;  // links to left and right subtrees
            public bool color;     // color of parent link, RED is TRUE, BLACK is FALSE
            public int size;          // subtree count

            public Node(Key key, Value val, bool color, int size)
            {
                this.key = key;
                this.val = val;
                this.color = color;
                this.size = size;
            }
        }

        /**
         * Initializes an empty symbol table.
         */
        public RedBlackBST()
        {
        }
        /***************************************************************************
    *  Node helper methods.
    ***************************************************************************/
        // is node x red; false if x is null ?
        private bool isRed(Node x)
        {
            if (x == null) return false;
            return x.color == RED;
        }

        // number of node in subtree rooted at x; 0 if x is null
        private int size(Node x)
        {
            if (x == null) return 0;
            return x.size;
        }
        /**
         * Returns the number of key-value pairs in this symbol table.
         * @return the number of key-value pairs in this symbol table
         */
        public int size()
        {
            return size(root);
        }

        /**
          * Is this symbol table empty?
          * @return {@code true} if this symbol table is empty and {@code false} otherwise
          */
        public bool isEmpty()
        {
            return root == null;
        }
        /***************************************************************************
    *  Standard BST search.
    ***************************************************************************/

        /**
         * Returns the value associated with the given key.
         * @param key the key
         * @return the value associated with the given key if the key is in the symbol table
         *     and {@code null} if the key is not in the symbol table
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public Value get(Key key)
        {
            if (key == null) throw new ArgumentException("argument to get() is null");
            return get(root, key);
        }

        // value associated with the given key in subtree rooted at x; null if no such key
        private Value get(Node x, Key key)
        {
            while (x != null)
            {
                int cmp = key.CompareTo(x.key);
                if (cmp < 0) x = x.left;
                else if (cmp > 0) x = x.right;
                else return x.val;
            }
            return default(Value);
        }

        /**
         * Does this symbol table contain the given key?
         * @param key the key
         * @return {@code true} if this symbol table contains {@code key} and
         *     {@code false} otherwise
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public bool contains(Key key)
        {
            return get(key) != null;
        }
        /***************************************************************************
    *  Red-black tree insertion.
    ***************************************************************************/

        /**
         * Inserts the specified key-value pair into the symbol table, overwriting the old 
         * value with the new value if the symbol table already contains the specified key.
         * Deletes the specified key (and its associated value) from this symbol table
         * if the specified value is {@code null}.
         *
         * @param key the key
         * @param val the value
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public void put(Key key, Value val)
        {
            if (key == null) throw new ArgumentException("first argument to put() is null");
            if (val == null)
            {
                delete(key);
                return;
            }

            root = put(root, key, val);
            root.color = BLACK;
            // assert check();
        }

        // insert the key-value pair in the subtree rooted at h
        private Node put(Node h, Key key, Value val)
        {
            if (h == null) return new Node(key, val, RED, 1);

            int cmp = key.CompareTo(h.key);
            if (cmp < 0) h.left = put(h.left, key, val);
            else if (cmp > 0) h.right = put(h.right, key, val);
            else h.val = val;

            // fix-up any right-leaning links
            if (isRed(h.right) && !isRed(h.left)) h = rotateLeft(h);
            if (isRed(h.left) && isRed(h.left.left)) h = rotateRight(h);
            if (isRed(h.left) && isRed(h.right)) flipColors(h);
            h.size = size(h.left) + size(h.right) + 1;

            return h;
        }
        /***************************************************************************
   *  Red-black tree deletion.
   ***************************************************************************/

        /**
         * Removes the smallest key and associated value from the symbol table.
         * @throws NoSuchElementException if the symbol table is empty
         */
        public void deleteMin()
        {
            if (isEmpty()) throw new ArgumentException("BST underflow");

            // if both children of root are black, set root to red
            if (!isRed(root.left) && !isRed(root.right))
                root.color = RED;

            root = deleteMin(root);
            if (!isEmpty()) root.color = BLACK;
            // assert check();
        }

        // delete the key-value pair with the minimum key rooted at h
        private Node deleteMin(Node h)
        {
            if (h.left == null)
                return null;

            if (!isRed(h.left) && !isRed(h.left.left))
                h = moveRedLeft(h);

            h.left = deleteMin(h.left);
            return balance(h);
        }


        /**
         * Removes the largest key and associated value from the symbol table.
         * @throws NoSuchElementException if the symbol table is empty
         */
        public void deleteMax()
        {
            if (isEmpty()) throw new ArgumentException("BST underflow");

            // if both children of root are black, set root to red
            if (!isRed(root.left) && !isRed(root.right))
                root.color = RED;

            root = deleteMax(root);
            if (!isEmpty()) root.color = BLACK;
            // assert check();
        }

        // delete the key-value pair with the maximum key rooted at h
        private Node deleteMax(Node h)
        {
            if (isRed(h.left))
                h = rotateRight(h);

            if (h.right == null)
                return null;

            if (!isRed(h.right) && !isRed(h.right.left))
                h = moveRedRight(h);

            h.right = deleteMax(h.right);

            return balance(h);
        }

        /**
         * Removes the specified key and its associated value from this symbol table     
         * (if the key is in this symbol table).    
         *
         * @param  key the key
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public void delete(Key key)
        {
            if (key == null) throw new ArgumentException("argument to delete() is null");
            if (!contains(key)) return;

            // if both children of root are black, set root to red
            if (!isRed(root.left) && !isRed(root.right))
                root.color = RED;

            root = delete(root, key);
            if (!isEmpty()) root.color = BLACK;
            // assert check();
        }

        // delete the key-value pair with the given key rooted at h
        private Node delete(Node h, Key key)
        {
            // assert get(h, key) != null;

            if (key.CompareTo(h.key) < 0)
            {
                if (!isRed(h.left) && !isRed(h.left.left))
                    h = moveRedLeft(h);
                h.left = delete(h.left, key);
            }
            else
            {
                if (isRed(h.left))
                    h = rotateRight(h);
                if (key.CompareTo(h.key) == 0 && (h.right == null))
                    return null;
                if (!isRed(h.right) && !isRed(h.right.left))
                    h = moveRedRight(h);
                if (key.CompareTo(h.key) == 0)
                {
                    Node x = min(h.right);
                    h.key = x.key;
                    h.val = x.val;
                    // h.val = get(h.right, min(h.right).key);
                    // h.key = min(h.right).key;
                    h.right = deleteMin(h.right);
                }
                else h.right = delete(h.right, key);
            }
            return balance(h);
        }

        /***************************************************************************
   *  Red-black tree helper functions.
   ***************************************************************************/

        // make a left-leaning link lean to the right
        private Node rotateRight(Node h)
        {
            // assert (h != null) && isRed(h.left);
            Node x = h.left;
            h.left = x.right;
            x.right = h;
            x.color = x.right.color;
            x.right.color = RED;
            x.size = h.size;
            h.size = size(h.left) + size(h.right) + 1;
            return x;
        }

        // make a right-leaning link lean to the left
        private Node rotateLeft(Node h)
        {
            // assert (h != null) && isRed(h.right);
            Node x = h.right;
            h.right = x.left;
            x.left = h;
            x.color = x.left.color;
            x.left.color = RED;
            x.size = h.size;
            h.size = size(h.left) + size(h.right) + 1;
            return x;
        }

        // flip the colors of a node and its two children
        private void flipColors(Node h)
        {
            // h must have opposite color of its two children
            // assert (h != null) && (h.left != null) && (h.right != null);
            // assert (!isRed(h) &&  isRed(h.left) &&  isRed(h.right))
            //    || (isRed(h)  && !isRed(h.left) && !isRed(h.right));
            h.color = !h.color;
            h.left.color = !h.left.color;
            h.right.color = !h.right.color;
        }

        // Assuming that h is red and both h.left and h.left.left
        // are black, make h.left or one of its children red.
        private Node moveRedLeft(Node h)
        {
            // assert (h != null);
            // assert isRed(h) && !isRed(h.left) && !isRed(h.left.left);

            flipColors(h);
            if (isRed(h.right.left))
            {
                h.right = rotateRight(h.right);
                h = rotateLeft(h);
                flipColors(h);
            }
            return h;
        }

        // Assuming that h is red and both h.right and h.right.left
        // are black, make h.right or one of its children red.
        private Node moveRedRight(Node h)
        {
            // assert (h != null);
            // assert isRed(h) && !isRed(h.right) && !isRed(h.right.left);
            flipColors(h);
            if (isRed(h.left.left))
            {
                h = rotateRight(h);
                flipColors(h);
            }
            return h;
        }

        // restore red-black tree invariant
        private Node balance(Node h)
        {
            // assert (h != null);

            if (isRed(h.right)) h = rotateLeft(h);
            if (isRed(h.left) && isRed(h.left.left)) h = rotateRight(h);
            if (isRed(h.left) && isRed(h.right)) flipColors(h);

            h.size = size(h.left) + size(h.right) + 1;
            return h;
        }
        /***************************************************************************
   *  Utility functions.
   ***************************************************************************/

        /**
         * Returns the height of the BST (for debugging).
         * @return the height of the BST (a 1-node tree has height 0)
         */
        public int height()
        {
            return height(root);
        }
        private int height(Node x)
        {
            if (x == null) return -1;
            return 1 + Math.Max(height(x.left), height(x.right));
        }
        /***************************************************************************
  *  Ordered symbol table methods.
  ***************************************************************************/

        /**
         * Returns the smallest key in the symbol table.
         * @return the smallest key in the symbol table
         * @throws NoSuchElementException if the symbol table is empty
         */
        public Key min()
        {
            if (isEmpty()) throw new ArgumentException("called min() with empty symbol table");
            return min(root).key;
        }

        // the smallest key in subtree rooted at x; null if no such key
        private Node min(Node x)
        {
            // assert x != null;
            if (x.left == null) return x;
            else return min(x.left);
        }

        /**
         * Returns the largest key in the symbol table.
         * @return the largest key in the symbol table
         * @throws NoSuchElementException if the symbol table is empty
         */
        public Key max()
        {
            if (isEmpty()) throw new ArgumentException("called max() with empty symbol table");
            return max(root).key;
        }

        // the largest key in the subtree rooted at x; null if no such key
        private Node max(Node x)
        {
            // assert x != null;
            if (x.right == null) return x;
            else return max(x.right);
        }


        /**
         * Returns the largest key in the symbol table less than or equal to {@code key}.
         * @param key the key
         * @return the largest key in the symbol table less than or equal to {@code key}
         * @throws NoSuchElementException if there is no such key
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public Key floor(Key key)
        {
            if (key == null) throw new ArgumentException("argument to floor() is null");
            if (isEmpty()) throw new ArgumentException("called floor() with empty symbol table");
            Node x = floor(root, key);
            if (x == null) return default(Key);
            else return x.key;
        }

        // the largest key in the subtree rooted at x less than or equal to the given key
        private Node floor(Node x, Key key)
        {
            if (x == null) return null;
            int cmp = key.CompareTo(x.key);
            if (cmp == 0) return x;
            if (cmp < 0) return floor(x.left, key);
            Node t = floor(x.right, key);
            if (t != null) return t;
            else return x;
        }

        /**
         * Returns the smallest key in the symbol table greater than or equal to {@code key}.
         * @param key the key
         * @return the smallest key in the symbol table greater than or equal to {@code key}
         * @throws NoSuchElementException if there is no such key
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public Key ceiling(Key key)
        {
            if (key == null) throw new ArgumentException("argument to ceiling() is null");
            if (isEmpty()) throw new ArgumentException("called ceiling() with empty symbol table");
            Node x = ceiling(root, key);
            if (x == null) return default(Key);
            else return x.key;
        }

        // the smallest key in the subtree rooted at x greater than or equal to the given key
        private Node ceiling(Node x, Key key)
        {
            if (x == null) return null;
            int cmp = key.CompareTo(x.key);
            if (cmp == 0) return x;
            if (cmp > 0) return ceiling(x.right, key);
            Node t = ceiling(x.left, key);
            if (t != null) return t;
            else return x;
        }

        /**
         * Return the kth smallest key in the symbol table.
         * @param k the order statistic
         * @return the {@code k}th smallest key in the symbol table
         * @throws IllegalArgumentException unless {@code k} is between 0 and
         *     <em>n</em>–1
         */
        public Key select(int k)
        {
            if (k < 0 || k >= size())
            {
                throw new ArgumentException("called select() with invalid argument: " + k);
            }
            Node x = select(root, k);
            return x.key;
        }

        // the key of rank k in the subtree rooted at x
        private Node select(Node x, int k)
        {
            // assert x != null;
            // assert k >= 0 && k < size(x);
            int t = size(x.left);
            if (t > k) return select(x.left, k);
            else if (t < k) return select(x.right, k - t - 1);
            else return x;
        }

        /**
         * Return the number of keys in the symbol table strictly less than {@code key}.
         * @param key the key
         * @return the number of keys in the symbol table strictly less than {@code key}
         * @throws IllegalArgumentException if {@code key} is {@code null}
         */
        public int rank(Key key)
        {
            if (key == null) throw new ArgumentException("argument to rank() is null");
            return rank(key, root);
        }

        // number of keys less than key in the subtree rooted at x
        private int rank(Key key, Node x)
        {
            if (x == null) return 0;
            int cmp = key.CompareTo(x.key);
            if (cmp < 0) return rank(key, x.left);
            else if (cmp > 0) return 1 + size(x.left) + rank(key, x.right);
            else return size(x.left);
        }

        /***************************************************************************
   *  Range count and range search.
   ***************************************************************************/

        /**
         * Returns all keys in the symbol table as an {@code Iterable}.
         * To iterate over all of the keys in the symbol table named {@code st},
         * use the foreach notation: {@code for (Key key : st.keys())}.
         * @return all keys in the symbol table as an {@code Iterable}
         */
        public IEnumerable<Key> keys()
        {
            if (isEmpty()) return new Queue<Key>();
            return keys(min(), max());
        }

        /**
         * Returns all keys in the symbol table in the given range,
         * as an {@code Iterable}.
         *
         * @param  lo minimum endpoint
         * @param  hi maximum endpoint
         * @return all keys in the sybol table between {@code lo} 
         *    (inclusive) and {@code hi} (inclusive) as an {@code Iterable}
         * @throws IllegalArgumentException if either {@code lo} or {@code hi}
         *    is {@code null}
         */
        public IEnumerable<Key> keys(Key lo, Key hi)
        {
            if (lo == null) throw new ArgumentException("first argument to keys() is null");
            if (hi == null) throw new ArgumentException("second argument to keys() is null");

            Queue<Key> queue = new Queue<Key>();
            // if (isEmpty() || lo.compareTo(hi) > 0) return queue;
            keys(root, queue, lo, hi);            
            return queue;
        }

        // add the keys between lo and hi in the subtree rooted at x
        // to the queue
        private void keys(Node x, Queue<Key> queue, Key lo, Key hi)
        {
            if (x == null) return;
            int cmplo = lo.CompareTo(x.key);
            int cmphi = hi.CompareTo(x.key);
            if (cmplo < 0) keys(x.left, queue, lo, hi);
            if (cmplo <= 0 && cmphi >= 0) queue.Enqueue(x.key);
            if (cmphi > 0) keys(x.right, queue, lo, hi);
        }

        /**
         * Returns the number of keys in the symbol table in the given range.
         *
         * @param  lo minimum endpoint
         * @param  hi maximum endpoint
         * @return the number of keys in the sybol table between {@code lo} 
         *    (inclusive) and {@code hi} (inclusive)
         * @throws IllegalArgumentException if either {@code lo} or {@code hi}
         *    is {@code null}
         */
        public int size(Key lo, Key hi)
        {
            if (lo == null) throw new ArgumentException("first argument to size() is null");
            if (hi == null) throw new ArgumentException("second argument to size() is null");

            if (lo.CompareTo(hi) > 0) return 0;
            if (contains(hi)) return rank(hi) - rank(lo) + 1;
            else return rank(hi) - rank(lo);
        }

        /***************************************************************************
   *  Check integrity of red-black tree data structure.
   ***************************************************************************/
        private bool check()
        {
            if (!isBST()) Console.WriteLine("Not in symmetric order");
            if (!isSizeConsistent()) Console.WriteLine("Subtree counts not consistent");
           // if (!isRankConsistent()) Console.WriteLine("Ranks not consistent");
            if (!is23()) Console.WriteLine("Not a 2-3 tree");
            if (!isBalanced()) Console.WriteLine("Not balanced");
            return isBST() && isSizeConsistent() /*&& isRankConsistent()*/ && is23() && isBalanced();
        }

        // does this binary tree satisfy symmetric order?
        // Note: this test also ensures that data structure is a binary tree since order is strict
        private bool isBST()
        {
            return isBST(root, default(Key), default(Key));
        }

        // is the tree rooted at x a BST with all keys strictly between min and max
        // (if min or max is null, treat as empty constraint)
        // Credit: Bob Dondero's elegant solution
        private bool isBST(Node x, Key min, Key max)
        {
            if (x == null) return true;
            if (min != null && x.key.CompareTo(min) <= 0) return false;
            if (max != null && x.key.CompareTo(max) >= 0) return false;
            return isBST(x.left, min, x.key) && isBST(x.right, x.key, max);
        }

        // are the size fields correct?
        private bool isSizeConsistent() { return isSizeConsistent(root); }
        private bool isSizeConsistent(Node x)
        {
            if (x == null) return true;
            if (x.size != size(x.left) + size(x.right) + 1) return false;
            return isSizeConsistent(x.left) && isSizeConsistent(x.right);
        }

        // check that ranks are consistent
        /*
        private bool isRankConsistent()
        {
            
            for (int i = 0; i < size(); i++)
                if (i != rank(select(i))) return false;
            for (Key key in keys())
                if (key.CompareTo(select(rank(key))) != 0) return false;
            return true;
            
        }
        */

        // Does the tree have no red right links, and at most one (left)
        // red links in a row on any path?
        private bool is23() { return is23(root); }
        private bool is23(Node x)
        {
            if (x == null) return true;
            if (isRed(x.right)) return false;
            if (x != root && isRed(x) && isRed(x.left))
                return false;
            return is23(x.left) && is23(x.right);
        }

        // do all paths from root to leaf have same number of black edges?
        private bool isBalanced()
        {
            int black = 0;     // number of black links on path from root to min
            Node x = root;
            while (x != null)
            {
                if (!isRed(x)) black++;
                x = x.left;
            }
            return isBalanced(root, black);
        }

        // does every path from the root to a leaf have the given number of black links?
        private bool isBalanced(Node x, int black)
        {
            if (x == null) return black == 0;
            if (!isRed(x)) black--;
            return isBalanced(x.left, black) && isBalanced(x.right, black);
        }

   
        //-------- iteraror
        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        public IEnumerator<Key> GetEnumerator()
        {
            return null;// NotImplementedException;
        }
    }
}

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using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace RedBlackBSTExample

{

class RedBlackBST<Key,Value>:IEnumerable where Key:IComparable

{

public bool RED = true;

public bool BLACK = false;

private Node root; // root of the BST

// BST helper node data type

private class Node

{

public Key key; // key

public Value val; // associated data

public Node left, right; // links to left and right subtrees

public bool color; // color of parent link, RED is TRUE, BLACK is FALSE

public int size; // subtree count

public Node(Key key, Value val, bool color, int size)

{

this.key = key;

this.val = val;

this.color = color;

this.size = size;

}

/**

* Initializes an empty symbol table.

public RedBlackBST()

{

}

/***************************************************************************

* Node helper methods.

***************************************************************************/

// is node x red; false if x is null ?

private bool isRed(Node x)

{

if (x == null) return false;

return x.color == RED;

}

// number of node in subtree rooted at x; 0 if x is null

private int size(Node x)

{

if (x == null) return 0;

return x.size;

}

/**

* Returns the number of key-value pairs in this symbol table.

* @return the number of key-value pairs in this symbol table

public int size()

{

return size(root);

}

/**

* Is this symbol table empty?

* @return {@code true} if this symbol table is empty and {@code false} otherwise

public bool isEmpty()

{

return root == null;

}

/***************************************************************************

* Standard BST search.

***************************************************************************/

/**

* Returns the value associated with the given key.

* @param key the key

* @return the value associated with the given key if the key is in the symbol table

* and {@code null} if the key is not in the symbol table

* @throws IllegalArgumentException if {@code key} is {@code null}

public Value get(Key key)

{

if (key == null) throw new ArgumentException("argument to get() is null");

return get(root, key);

}

// value associated with the given key in subtree rooted at x; null if no such key

private Value get(Node x, Key key)

{

while (x != null)

{

int cmp = key.CompareTo(x.key);

if (cmp < 0) x = x.left;

else if (cmp > 0) x = x.right;

else return x.val;

}

return default(Value);

}

/**

* Does this symbol table contain the given key?

* @param key the key

* @return {@code true} if this symbol table contains {@code key} and

* {@code false} otherwise

* @throws IllegalArgumentException if {@code key} is {@code null}

public bool contains(Key key)

{

return get(key) != null;

}

/***************************************************************************

* Red-black tree insertion.

***************************************************************************/

/**

* Inserts the specified key-value pair into the symbol table, overwriting the old

* value with the new value if the symbol table already contains the specified key.

* Deletes the specified key (and its associated value) from this symbol table

* if the specified value is {@code null}.

* @param key the key

* @param val the value

* @throws IllegalArgumentException if {@code key} is {@code null}

public void put(Key key, Value val)

{

if (key == null) throw new ArgumentException("first argument to put() is null");

if (val == null)

{

delete(key);

return;

}

root = put(root, key, val);

root.color = BLACK;

// assert check();

}

// insert the key-value pair in the subtree rooted at h

private Node put(Node h, Key key, Value val)

{

if (h == null) return new Node(key, val, RED, 1);

int cmp = key.CompareTo(h.key);

if (cmp < 0) h.left = put(h.left, key, val);

else if (cmp > 0) h.right = put(h.right, key, val);

else h.val = val;

// fix-up any right-leaning links

if (isRed(h.right) && !isRed(h.left)) h = rotateLeft(h);

if (isRed(h.left) && isRed(h.left.left)) h = rotateRight(h);

if (isRed(h.left) && isRed(h.right)) flipColors(h);

h.size = size(h.left) + size(h.right) + 1;

return h;

}

/***************************************************************************

* Red-black tree deletion.

***************************************************************************/

/**

* Removes the smallest key and associated value from the symbol table.

* @throws NoSuchElementException if the symbol table is empty

public void deleteMin()

{

if (isEmpty()) throw new ArgumentException("BST underflow");

// if both children of root are black, set root to red

if (!isRed(root.left) && !isRed(root.right))

root.color = RED;

root = deleteMin(root);

if (!isEmpty()) root.color = BLACK;

// assert check();

}

// delete the key-value pair with the minimum key rooted at h

private Node deleteMin(Node h)

{

if (h.left == null)

return null;

if (!isRed(h.left) && !isRed(h.left.left))

h = moveRedLeft(h);

h.left = deleteMin(h.left);

return balance(h);

}

/**

* Removes the largest key and associated value from the symbol table.

* @throws NoSuchElementException if the symbol table is empty

public void deleteMax()

{

if (isEmpty()) throw new ArgumentException("BST underflow");

// if both children of root are black, set root to red

if (!isRed(root.left) && !isRed(root.right))

root.color = RED;

root = deleteMax(root);

if (!isEmpty()) root.color = BLACK;

// assert check();

}

// delete the key-value pair with the maximum key rooted at h

private Node deleteMax(Node h)

{

if (isRed(h.left))

h = rotateRight(h);

if (h.right == null)

return null;

if (!isRed(h.right) && !isRed(h.right.left))

h = moveRedRight(h);

h.right = deleteMax(h.right);

return balance(h);

}

/**

* Removes the specified key and its associated value from this symbol table

* (if the key is in this symbol table).

* @param key the key

* @throws IllegalArgumentException if {@code key} is {@code null}

public void delete(Key key)

{

if (key == null) throw new ArgumentException("argument to delete() is null");

if (!contains(key)) return;

// if both children of root are black, set root to red

if (!isRed(root.left) && !isRed(root.right))

root.color = RED;

root = delete(root, key);

if (!isEmpty()) root.color = BLACK;

// assert check();

}

// delete the key-value pair with the given key rooted at h

private Node delete(Node h, Key key)

{

// assert get(h, key) != null;

if (key.CompareTo(h.key) < 0)

{

if (!isRed(h.left) && !isRed(h.left.left))

h = moveRedLeft(h);

h.left = delete(h.left, key);

}

else

{

if (isRed(h.left))

h = rotateRight(h);

if (key.CompareTo(h.key) == 0 && (h.right == null))

return null;

if (!isRed(h.right) && !isRed(h.right.left))

h = moveRedRight(h);

if (key.CompareTo(h.key) == 0)

{

Node x = min(h.right);

h.key = x.key;

h.val = x.val;

// h.val = get(h.right, min(h.right).key);

// h.key = min(h.right).key;

h.right = deleteMin(h.right);

}

else h.right = delete(h.right, key);

}

return balance(h);

}

/***************************************************************************

* Red-black tree helper functions.

***************************************************************************/

// make a left-leaning link lean to the right

private Node rotateRight(Node h)

{

// assert (h != null) && isRed(h.left);

Node x = h.left;

h.left = x.right;

x.right = h;

x.color = x.right.color;

x.right.color = RED;

x.size = h.size;

h.size = size(h.left) + size(h.right) + 1;

return x;

}

// make a right-leaning link lean to the left

private Node rotateLeft(Node h)

{

// assert (h != null) && isRed(h.right);

Node x = h.right;

h.right = x.left;

x.left = h;

x.color = x.left.color;

x.left.color = RED;

x.size = h.size;

h.size = size(h.left) + size(h.right) + 1;

return x;

}

// flip the colors of a node and its two children

private void flipColors(Node h)

{

// h must have opposite color of its two children

// assert (h != null) && (h.left != null) && (h.right != null);

// assert (!isRed(h) && isRed(h.left) && isRed(h.right))

// || (isRed(h) && !isRed(h.left) && !isRed(h.right));

h.color = !h.color;

h.left.color = !h.left.color;

h.right.color = !h.right.color;

}

// Assuming that h is red and both h.left and h.left.left

// are black, make h.left or one of its children red.

private Node moveRedLeft(Node h)

{

// assert (h != null);

// assert isRed(h) && !isRed(h.left) && !isRed(h.left.left);

flipColors(h);

if (isRed(h.right.left))

{

h.right = rotateRight(h.right);

h = rotateLeft(h);

flipColors(h);

}

return h;

}

// Assuming that h is red and both h.right and h.right.left

// are black, make h.right or one of its children red.

private Node moveRedRight(Node h)

{

// assert (h != null);

// assert isRed(h) && !isRed(h.right) && !isRed(h.right.left);

flipColors(h);

if (isRed(h.left.left))

{

h = rotateRight(h);

flipColors(h);

}

return h;

}

// restore red-black tree invariant

private Node balance(Node h)

{

// assert (h != null);

if (isRed(h.right)) h = rotateLeft(h);

if (isRed(h.left) && isRed(h.left.left)) h = rotateRight(h);

if (isRed(h.left) && isRed(h.right)) flipColors(h);

h.size = size(h.left) + size(h.right) + 1;

return h;

}

/***************************************************************************

* Utility functions.

***************************************************************************/

/**

* Returns the height of the BST (for debugging).

* @return the height of the BST (a 1-node tree has height 0)

public int height()

{

return height(root);

}

private int height(Node x)

{

if (x == null) return -1;

return 1 + Math.Max(height(x.left), height(x.right));

}

/***************************************************************************

* Ordered symbol table methods.

***************************************************************************/

/**

* Returns the smallest key in the symbol table.

* @return the smallest key in the symbol table

* @throws NoSuchElementException if the symbol table is empty

public Key min()

{

if (isEmpty()) throw new ArgumentException("called min() with empty symbol table");

return min(root).key;

}

// the smallest key in subtree rooted at x; null if no such key

private Node min(Node x)

{

// assert x != null;

if (x.left == null) return x;

else return min(x.left);

}

/**

* Returns the largest key in the symbol table.

* @return the largest key in the symbol table

* @throws NoSuchElementException if the symbol table is empty

public Key max()

{

if (isEmpty()) throw new ArgumentException("called max() with empty symbol table");

return max(root).key;

}

// the largest key in the subtree rooted at x; null if no such key

private Node max(Node x)

{

// assert x != null;

if (x.right == null) return x;

else return max(x.right);

}

/**

* Returns the largest key in the symbol table less than or equal to {@code key}.

* @param key the key

* @return the largest key in the symbol table less than or equal to {@code key}

* @throws NoSuchElementException if there is no such key

* @throws IllegalArgumentException if {@code key} is {@code null}

public Key floor(Key key)

{

if (key == null) throw new ArgumentException("argument to floor() is null");

if (isEmpty()) throw new ArgumentException("called floor() with empty symbol table");

Node x = floor(root, key);

if (x == null) return default(Key);

else return x.key;

}

// the largest key in the subtree rooted at x less than or equal to the given key

private Node floor(Node x, Key key)

{

if (x == null) return null;

int cmp = key.CompareTo(x.key);

if (cmp == 0) return x;

if (cmp < 0) return floor(x.left, key);

Node t = floor(x.right, key);

if (t != null) return t;

else return x;

}

/**

* Returns the smallest key in the symbol table greater than or equal to {@code key}.

* @param key the key

* @return the smallest key in the symbol table greater than or equal to {@code key}

* @throws NoSuchElementException if there is no such key

* @throws IllegalArgumentException if {@code key} is {@code null}

public Key ceiling(Key key)

{

if (key == null) throw new ArgumentException("argument to ceiling() is null");

if (isEmpty()) throw new ArgumentException("called ceiling() with empty symbol table");

Node x = ceiling(root, key);

if (x == null) return default(Key);

else return x.key;

}

// the smallest key in the subtree rooted at x greater than or equal to the given key

private Node ceiling(Node x, Key key)

{

if (x == null) return null;

int cmp = key.CompareTo(x.key);

if (cmp == 0) return x;

if (cmp > 0) return ceiling(x.right, key);

Node t = ceiling(x.left, key);

if (t != null) return t;

else return x;

}

/**

* Return the kth smallest key in the symbol table.

* @param k the order statistic

* @return the {@code k}th smallest key in the symbol table

* @throws IllegalArgumentException unless {@code k} is between 0 and

* n–1

public Key select(int k)

{

if (k < 0 || k >= size())

{

throw new ArgumentException("called select() with invalid argument: " + k);

}

Node x = select(root, k);

return x.key;

}

// the key of rank k in the subtree rooted at x

private Node select(Node x, int k)

{

// assert x != null;

// assert k >= 0 && k < size(x);

int t = size(x.left);

if (t > k) return select(x.left, k);

else if (t < k) return select(x.right, k - t - 1);

else return x;

}

/**

* Return the number of keys in the symbol table strictly less than {@code key}.

* @param key the key

* @return the number of keys in the symbol table strictly less than {@code key}

* @throws IllegalArgumentException if {@code key} is {@code null}

public int rank(Key key)

{

if (key == null) throw new ArgumentException("argument to rank() is null");

return rank(key, root);

}

// number of keys less than key in the subtree rooted at x

private int rank(Key key, Node x)

{

if (x == null) return 0;

int cmp = key.CompareTo(x.key);

if (cmp < 0) return rank(key, x.left);

else if (cmp > 0) return 1 + size(x.left) + rank(key, x.right);

else return size(x.left);

}

/***************************************************************************

* Range count and range search.

***************************************************************************/

/**

* Returns all keys in the symbol table as an {@code Iterable}.

* To iterate over all of the keys in the symbol table named {@code st},

* use the foreach notation: {@code for (Key key : st.keys())}.

* @return all keys in the symbol table as an {@code Iterable}

public IEnumerable<Key> keys()

{

if (isEmpty()) return new Queue<Key>();

return keys(min(), max());

}

/**

* Returns all keys in the symbol table in the given range,

* as an {@code Iterable}.

* @param lo minimum endpoint

* @param hi maximum endpoint

* @return all keys in the sybol table between {@code lo}

* (inclusive) and {@code hi} (inclusive) as an {@code Iterable}

* @throws IllegalArgumentException if either {@code lo} or {@code hi}

* is {@code null}

public IEnumerable<Key> keys(Key lo, Key hi)

{

if (lo == null) throw new ArgumentException("first argument to keys() is null");

if (hi == null) throw new ArgumentException("second argument to keys() is null");

Queue<Key> queue = new Queue<Key>();

// if (isEmpty() || lo.compareTo(hi) > 0) return queue;

keys(root, queue, lo, hi);

return queue;

}

// add the keys between lo and hi in the subtree rooted at x

// to the queue

private void keys(Node x, Queue<Key> queue, Key lo, Key hi)

{

if (x == null) return;

int cmplo = lo.CompareTo(x.key);

int cmphi = hi.CompareTo(x.key);

if (cmplo < 0) keys(x.left, queue, lo, hi);

if (cmplo <= 0 && cmphi >= 0) queue.Enqueue(x.key);

if (cmphi > 0) keys(x.right, queue, lo, hi);

}

/**

* Returns the number of keys in the symbol table in the given range.

* @param lo minimum endpoint

* @param hi maximum endpoint

* @return the number of keys in the sybol table between {@code lo}

* (inclusive) and {@code hi} (inclusive)

* @throws IllegalArgumentException if either {@code lo} or {@code hi}

* is {@code null}

public int size(Key lo, Key hi)

{

if (lo == null) throw new ArgumentException("first argument to size() is null");

if (hi == null) throw new ArgumentException("second argument to size() is null");

if (lo.CompareTo(hi) > 0) return 0;

if (contains(hi)) return rank(hi) - rank(lo) + 1;

else return rank(hi) - rank(lo);

}

/***************************************************************************

* Check integrity of red-black tree data structure.

***************************************************************************/

private bool check()

{

if (!isBST()) Console.WriteLine("Not in symmetric order");

if (!isSizeConsistent()) Console.WriteLine("Subtree counts not consistent");

// if (!isRankConsistent()) Console.WriteLine("Ranks not consistent");

if (!is23()) Console.WriteLine("Not a 2-3 tree");

if (!isBalanced()) Console.WriteLine("Not balanced");

return isBST() && isSizeConsistent() /*&& isRankConsistent()*/ && is23() && isBalanced();

}

// does this binary tree satisfy symmetric order?

// Note: this test also ensures that data structure is a binary tree since order is strict

private bool isBST()

{

return isBST(root, default(Key), default(Key));

}

// is the tree rooted at x a BST with all keys strictly between min and max

// (if min or max is null, treat as empty constraint)

// Credit: Bob Dondero's elegant solution

private bool isBST(Node x, Key min, Key max)

{

if (x == null) return true;

if (min != null && x.key.CompareTo(min) <= 0) return false;

if (max != null && x.key.CompareTo(max) >= 0) return false;

return isBST(x.left, min, x.key) && isBST(x.right, x.key, max);

}

// are the size fields correct?

private bool isSizeConsistent() { return isSizeConsistent(root); }

private bool isSizeConsistent(Node x)

{

if (x == null) return true;

if (x.size != size(x.left) + size(x.right) + 1) return false;

return isSizeConsistent(x.left) && isSizeConsistent(x.right);

}

// check that ranks are consistent

private bool isRankConsistent()

{

for (int i = 0; i < size(); i++)

if (i != rank(select(i))) return false;

for (Key key in keys())

if (key.CompareTo(select(rank(key))) != 0) return false;

return true;

}

// Does the tree have no red right links, and at most one (left)

// red links in a row on any path?

private bool is23() { return is23(root); }

private bool is23(Node x)

{

if (x == null) return true;

if (isRed(x.right)) return false;

if (x != root && isRed(x) && isRed(x.left))

return false;

return is23(x.left) && is23(x.right);

}

// do all paths from root to leaf have same number of black edges?

private bool isBalanced()

{

int black = 0; // number of black links on path from root to min

Node x = root;

while (x != null)

{

if (!isRed(x)) black++;

x = x.left;

}

return isBalanced(root, black);

}

// does every path from the root to a leaf have the given number of black links?

private bool isBalanced(Node x, int black)

{

if (x == null) return black == 0;

if (!isRed(x)) black--;

return isBalanced(x.left, black) && isBalanced(x.right, black);

}

//-------- iteraror

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

return GetEnumerator();

}

public IEnumerator<Key> GetEnumerator()

{

return null;// NotImplementedException;

}

Posted in C# | Comments Off

C#. BinarySearchTree – Traverse ways

Posted on 29.09.2017 by Stanislav_Panteleev

Source In this example binary tree is built… we just take a look on traversies Binary Search Tree A Binary Search Tree is a binary tree with a search property where elements in the left sub-tree are less than the … Continue reading →

Posted in C# | Comments Off

C#.Algo.BinarySearchTree

Posted on 29.09.2017 by Stanislav_Panteleev

From JaseWick, source… Example shows how to search, using Binary Tree, built on 2 pointers linked list Also a lot of other methods in BST class… Git Main and tests

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BinarySearchTreeExample
{
    class Program
    {
        static void Main(string[] args)
        {
            //Standart_TestClient sc = new Standart_TestClient();
            //sc.Execute();

            FrequencyCounter_TestClient fct = new FrequencyCounter_TestClient();
            fct.Execute();

            Console.ReadLine();
        }
    }

    public class Standart_TestClient
    {
        string[] a =  {
                "S",
                "E",
                "A",
                "R",
                "C",
                "H",
                "E",
                "X",
                "A",
                "M",
                "P",
                "L",
                "E"
            };
        public void Execute()
        {

            BST<string, int> st = new BST<string, int>();
            //Array.Sort(a); // we sort because we use binary search inside

            //adding
            for (int i = 0; i < a.Length; i++)
            {
                st.put(a[i], i);
            }
            if (st.contains("X")) Console.WriteLine("Yes! Contains X");
            st.ConsoleDisplay();
            st.delete("L");
            // Console.WriteLine();
            st.ConsoleDisplay();
        }
    }

    public class FrequencyCounter_TestClient
    {
        string[] a =  {
                "S",
                "E",
                "A",
                "R",
                "C",
                "H",
                "E",
                "X",
                "A",
                "M",
                "P",
                "L",
                "E"
            };


        public void Execute()
        {
            BST<string, int> st = new BST<string, int>();
            //adding
            for (int i = 0; i < a.Length; i++)
            {
                // to Key we write Word, to Value we write Frequency
                if (!st.contains(a[i])) st.put(a[i], 1);
                else st.put(a[i], st.get(a[i]) + 1);
            }
            st.ConsoleDisplay();
            // search max frequent word
            string maxFrequentWord = " ";
            st.put(maxFrequentWord, 0);

            foreach (var val in st)
            {
                if ((val != null) && (st.get(val) > st.get(maxFrequentWord))) maxFrequentWord = val;
            }
            Console.WriteLine("maxFrequentWord=" + maxFrequentWord + " maxFrequency " + st.get(maxFrequentWord));
            st.ConsoleDisplay();
        }

    }

}

100

101

102

103

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace BinarySearchTreeExample

{

class Program

{

static void Main(string[] args)

{

//Standart_TestClient sc = new Standart_TestClient();

//sc.Execute();

FrequencyCounter_TestClient fct = new FrequencyCounter_TestClient();

fct.Execute();

Console.ReadLine();

}

public class Standart_TestClient

{

string[] a = {

"S",

"E",

"A",

"R",

"C",

"H",

"E",

"X",

"A",

"M",

"P",

"L",

"E"

};

public void Execute()

{

BST<string, int> st = new BST<string, int>();

//Array.Sort(a); // we sort because we use binary search inside

//adding

for (int i = 0; i < a.Length; i++)

{

st.put(a[i], i);

}

if (st.contains("X")) Console.WriteLine("Yes! Contains X");

st.ConsoleDisplay();

st.delete("L");

// Console.WriteLine();

st.ConsoleDisplay();

}

public class FrequencyCounter_TestClient

{

string[] a = {

"S",

"E",

"A",

"R",

"C",

"H",

"E",

"X",

"A",

"M",

"P",

"L",

"E"

};

public void Execute()

{

BST<string, int> st = new BST<string, int>();

//adding

for (int i = 0; i < a.Length; i++)

{

// to Key we write Word, to Value we write Frequency

if (!st.contains(a[i])) st.put(a[i], 1);

else st.put(a[i], st.get(a[i]) + 1);

}

st.ConsoleDisplay();

// search max frequent word

string maxFrequentWord = " ";

st.put(maxFrequentWord, 0);

foreach (var val in st)

{

if ((val != null) && (st.get(val) > st.get(maxFrequentWord))) maxFrequentWord = val;

}

Console.WriteLine("maxFrequentWord=" + maxFrequentWord + " maxFrequency " + st.get(maxFrequentWord));

st.ConsoleDisplay();

}

Только Get и Put

 class BST<Key, Value> : IEnumerable<Key> where Key : IComparable
    {
        private Node root;

        public class Node
        {
            public Key key;
            public Value val; 
            public Node left,right; // left and right subtrees
            public int size; // number of nodes in subtree

            public Node(Key key, Value val, int size)
            {
                this.key = key;
                this.val = val;
                this.size = size;
            }
        }

        public Value Get(Key key)
        {
            return Get(root, key);
        }         

        private Value Get(Node x, Key key)
        {
            if (key == null) throw new ArgumentException("called get() with a null key");
            if (x == null) return default(Value);
            int cmp = key.CompareTo(x.key);
            if (cmp < 0) return Get(x.left, key);
            else if (cmp > 0) return Get(x.right, key);
            else return x.val;
        }


        public void Put(Key key, Value val)
        {
            root = Put(root, key, val);
        }
        public Node Put(Node x,Key key,Value val)
        {
            if (x == null) return new Node(key,val,1);
            int cmp = key.CompareTo(x.key);
            if (cmp < 0) x.left = Put(x.left, key, val);
            if (cmp > 0) x.right = Put(x.right, key, val);
            else x.val = val;
            x.size = 1 + Size(x.left) + Size(x.right);
            return x;
        }

        
        //
        public int Size(Node x)
        {
            if (x == null) return 0;
            else return x.size;
        }
        private void TraverseBinaryTreeKey(Node x, ref Queue<Key> q)
        {
            if (x != null)
            {
                q.Enqueue(x.key);
                TraverseBinaryTreeKey(x.left, ref q);
                TraverseBinaryTreeKey(x.right, ref q);
            }
        }

        public IEnumerator<Key> GetEnumerator()
        {
            Queue<Key> q = new Queue<Key>();
            TraverseBinaryTreeKey(root, ref q);
            return q.GetEnumerator();
        }


        IEnumerator IEnumerable.GetEnumerator()
        {            
            return GetEnumerator();
        }

class BST<Key, Value> : IEnumerable<Key> where Key : IComparable

{

private Node root;

public class Node

{

public Key key;

public Value val;

public Node left,right; // left and right subtrees

public int size; // number of nodes in subtree

public Node(Key key, Value val, int size)

{

this.key = key;

this.val = val;

this.size = size;

}

public Value Get(Key key)

{

return Get(root, key);

}

private Value Get(Node x, Key key)

{

if (key == null) throw new ArgumentException("called get() with a null key");

if (x == null) return default(Value);

int cmp = key.CompareTo(x.key);

if (cmp < 0) return Get(x.left, key);

else if (cmp > 0) return Get(x.right, key);

else return x.val;

}

public void Put(Key key, Value val)

{

root = Put(root, key, val);

}

public Node Put(Node x,Key key,Value val)

{

if (x == null) return new Node(key,val,1);

int cmp = key.CompareTo(x.key);

if (cmp < 0) x.left = Put(x.left, key, val);

if (cmp > 0) x.right = Put(x.right, key, val);

else x.val = val;

x.size = 1 + Size(x.left) + Size(x.right);

return x;

}

public int Size(Node x)

{

if (x == null) return 0;

else return x.size;

}

private void TraverseBinaryTreeKey(Node x, ref Queue<Key> q)

{

if (x != null)

{

q.Enqueue(x.key);

TraverseBinaryTreeKey(x.left, ref q);

TraverseBinaryTreeKey(x.right, ref q);

}

public IEnumerator<Key> GetEnumerator()

{

Queue<Key> q = new Queue<Key>();

TraverseBinaryTreeKey(root, ref q);

return q.GetEnumerator();

}

IEnumerator IEnumerable.GetEnumerator()

{

return GetEnumerator();

}

Git Binary Search … Continue reading →

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Category Archives: C#

C#.Algo.SymbolGraph

C#. Algo.Graph. ClosableVertexSearch

С#.Algo.Graph.BreathFindSearch

С#.Algo.Graph.DepthFindSearch

С#. Graph on linked lists

C#. LinearProbingHashST

C#. Algo. SeparateChainingHashST – hashing with separate chains

C#.Algo.RedBlackBST

C#. BinarySearchTree – Traverse ways

C#.Algo.BinarySearchTree

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