C#图与图的算法之广度优先遍历

上篇文章介绍了深度优先遍历，同时也介绍了广度优先遍历的思想，这里直接上代码：

using System;
using System.Collections.Generic;
using static System.Console;

namespace 图的广度优先遍历
{
    class Node
    {
        public int item;
        public Node next;
        public Node(int a)
        {
            item = a;
            next = null;
        }
    }
    class GraphLink
    {
        public Node first;
        public Node last;
        public GraphLink()
        {
            first = null;
            last = null;
        }
        public void Insert(int a)
        {
            Node newnode = new Node(a);
            if(first == null)
            {
                first = newnode;
                last = newnode;
            }
            else
            {
                last.next = newnode;
                last = newnode;
            }
        }
        public void Print()
        {
            Node current = first;
            while(current != null)
            {
                Write("[" + current.item + "]");
                current = current.next;
            }
            WriteLine();
        }
    }
    class Program
    {
        public static int[] run = new int[9];
        public static GraphLink[] head = new GraphLink[9];
        public const int MaxSize = 10;
        public static  Queue<int> queue = new Queue<int>();
        public static void BFS(int current)
        {
            Node temp;
            queue.Enqueue(current);
            run[current] = 1;
            Write("[" + current + "]");
            while( queue.Count > 0)
            {
                current = queue.Dequeue();
                temp = head[current].first;
                while(temp != null)
                {
                    if(run[temp.item] == 0)
                    {
                        queue.Enqueue(temp.item);
                        run[temp.item] = 1;
                        Write("[" + temp.item + "]");
                    }
                    temp = temp.next;
                }
            }
        }

        static void Main(string[] args)
        {
            int[,] data = { { 1, 2 }, { 2, 1 }, { 1, 3 }, { 3, 1 }, { 2,4},
                                        { 4,2},{ 2,5},{ 5,2},{ 3,6},{ 6,3},
                                        { 3,7},{ 7,3},{ 4,5},{ 5,4},{ 6,7},
                                        {7,6},{ 5,8},{ 8,5},{ 6,8},{ 8,6} };
            int DataNum;
            int i, j;
            WriteLine("图的邻接链表内容：");
            for ( i = 1;  i < 9;  i++)
            {
                run[i] = 0;
                head[i] = new GraphLink();
                Write("顶点" + i + "=>");
                for ( j = 0; j < 20; j++)
                {
                    if(data[j,0] == i)
                    {
                        DataNum = data[j, 1];
                        head[i].Insert(DataNum);
                    }
                }
                head[i].Print();

            }
            WriteLine("广度优先遍历:");
            BFS(1);
            WriteLine();
            ReadKey();
        }
    }
}

真的跟二叉树的层序遍历一模一样哈~真喜欢优雅的队列