c#实现Prim算法

using System;

using System.Collections.Generic;

using System.Linq;

namespace Prim算法

{

    ///

    /// 顶点

    ///

    public class Vertex

    {

        public String key;

        public Vertex(String key)

        {

            this.key = key;

        }

    }

    ///

    /// 边

    ///

    public class Edge

    {

        public Vertex start;

        public Vertex end;

        public int key;

        public Edge(Vertex start, Vertex end, int key)

        {

            this.start = start;

            this.end = end;

            this.key = key;

        }

    }

    public class Prim

    {

        public static List vertexList = new List();//结点集

        public static List EdgeQueue = new List();//边集

        public static List newVertex = new List();//已经 访问过的结点

        public static void buildGraph()

        {

            Vertex v1 = new Vertex("a");

            Prim.vertexList.Add(v1);

            Vertex v2 = new Vertex("b");

            Prim.vertexList.Add(v2);

            Vertex v3 = new Vertex("c");

            Prim.vertexList.Add(v3);

            Vertex v4 = new Vertex("d");

            Prim.vertexList.Add(v4);

            Vertex v5 = new Vertex("e");

            Prim.vertexList.Add(v5);

            addEdge(v1, v2, 6);

            addEdge(v1, v3, 7);

            addEdge(v2, v3, 8);

            addEdge(v2, v5, 4);

            addEdge(v2, v4, 5);

            addEdge(v3, v4, 3);

            addEdge(v3, v5, 9);

            addEdge(v5, v4, 7);

            addEdge(v5, v1, 2);

            //addEdge(v4, v2, 2);

        }

        public static void addEdge(Vertex a, Vertex b, int w)

        {

            Edge e = new Edge(a, b, w);

            Prim.EdgeQueue.Add(e);

        }

        public static void primTree()

        {

            buildGraph();

            Vertex start = vertexList.ElementAt(0);

            newVertex.Add(start);

            for (int n = 0; n < vertexList.Count; n++)

            {

                Vertex temp = new Vertex(start.key);

                Edge tempedge = new Edge(start, start, 1000);

                foreach (Vertex v in newVertex)

                {

                    foreach (Edge e in EdgeQueue)

                    {

                        if (e.start == v && !containVertex(e.end))

                        {

                            if (e.key < tempedge.key)

                            {

                                temp = e.end;

                                tempedge = e;

                            }

                        }

                    }

                }

                if (!containVertex(temp))

                {

                    newVertex.Add(temp);

                }

            }

            foreach (Vertex item in newVertex)

            {

                Console.WriteLine(item.key);

            }

        }

        public static bool containVertex(Vertex vte)

        {

            foreach (Vertex v in newVertex)

            {

                if (v.key.Equals(vte.key))

                    return true;

            }

            return false;

        }

        public static void Main(String[] args)

        {

            primTree();

        }

    }

}