迪杰斯特拉算法 计算两点之间最短距离

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

//迪杰斯特拉算法 计算两点最短距离
namespace Dijkstra
{
class Program
{
/// <summary>
/// 邻接矩阵
/// </summary>
private static int?[,] rectMatrix;

/// <summary>
/// 点 的距离
/// </summary>
private static int[] distanse;

/// <summary>
/// 访问过的点
/// </summary>
private static int[] visitPoints;

/// <summary>
/// 路径
/// </summary>
private static string[] path;

/// <summary>
/// 坐标点数量
/// </summary>
private static int pointNum = 10;

/// <summary>
/// 起始点
/// </summary>
private static int startPoint;

/// <summary>
/// 终点
/// </summary>
private static int endPoint;

static void Main(string[] args)
{
visitPoints = new int[pointNum];
distanse = new int[pointNum];
path = new string[pointNum];
initRectMatrix();
Console.WriteLine("请输入起始点坐标:");
string strPoint = Console.ReadLine();
Console.WriteLine("请输入终点坐标:");
string ePoint = Console.ReadLine();
if (Int32.TryParse(strPoint, out startPoint) && Int32.TryParse(ePoint, out endPoint))
{
computePath(startPoint);
Console.WriteLine("最佳路径:" + path[endPoint]);
Console.WriteLine("最短距离:" + distanse[endPoint]);
Console.ReadLine();
}
}

/// <summary>
/// 计算路径
/// </summary>
/// <param name="index"></param>
private static void computePath(int index)
{
//设置为1，标记当前点已经遍历
visitPoints[index] = 1;
if (isCurIndex(index))
{
int curDistanse;
for (int i = 0; i < pointNum; i++)
{
if (i != index && rectMatrix[index, i] != null)
{
curDistanse = distanse[index] == 0 ? 0 : (int)distanse[index];
if (curDistanse + rectMatrix[index, i] < distanse[i] || distanse[i] == 0)
{
distanse[i] = curDistanse + (int)rectMatrix[index, i];
if (index == startPoint)
{
path[i] = startPoint.ToString() + "=>" + i.ToString();
}
else
{
path[i] = path[index].ToString() + "=>" + i.ToString();
computePath(i);
}
}
}
}
}

int visit = getVisitIndex();
if (visit != -1)
{
computePath(visit);
}
}

/// <summary>
/// 得到未访问节点的最小索引
/// </summary>
/// <returns></returns>
private static int getVisitIndex()
{
int index=-1;
for(int i=0;i<pointNum;i++)
{
if (visitPoints[i] != 1)
{
index = i;
break;
}
}
return index;
}

/// <summary>
/// 判断当前节点是否与上一节点相连
/// </summary>
/// <param name="index"></param>
/// <returns></returns>
private static bool isCurIndex(int index)
{
if (index == startPoint ||(path[index] != null
&& path[index].IndexOf(index.ToString()) != -1))
{
return true;
}
return false;
}
/// <summary>
/// 初始化邻接矩阵
/// </summary>
private static void initRectMatrix()
{
rectMatrix = new int?[pointNum, pointNum];

rectMatrix[0, 1] = 15;
rectMatrix[0, 2] = 20;
rectMatrix[1, 3] = 30;
rectMatrix[1, 2] = 30;
rectMatrix[1, 4] = 20;
rectMatrix[1, 5] = 30;
rectMatrix[2, 3] = 30;
rectMatrix[2, 4] = 20;
rectMatrix[2, 6] = 30;
rectMatrix[3, 5] = 30;
rectMatrix[4, 7] = 20;
rectMatrix[4, 8] = 30;
rectMatrix[5, 6] = 30;
rectMatrix[6, 9] = 20;
rectMatrix[7, 8] = 30;
rectMatrix[7, 9] = 30;
rectMatrix[8, 4] = 20;
rectMatrix[8, 0] = 30;
rectMatrix[8, 3] = 30;
rectMatrix[9, 2] = 20;
rectMatrix[9, 7] = 30;
rectMatrix[9, 6] = 30;

for (int i = 0; i < pointNum; i++)
{
rectMatrix[i, i] = 0;
}
}
}
}