一个dijkstra的简单算法

#include <cstdlib>
#include <iostream>
#define LENGTH  100
#define Maxint  1000000
using namespace std;
int main(int argc, char *argv[])
{
//图G的点数N和边数M
int N,M,i,j;

//边的起点和终点
int E[LENGTH][2];
//边的权值
int Value[LENGTH];

//分别是当前选边的权值‘选边的编号和树的长度
// int Min,MinE,ValueT;

//读入图G，图G采用边目录表示法
cin>>N>>M;

int c[LENGTH][LENGTH];
for( i = 0; i <= N; i++)
for(j = 0; j <= N; j++)
c[i][j] = Maxint;

//初始化
for (i=0;i<M;i++)
{ cin>>E[i][0]>>E[i][1]>>Value[i];
c[E[i][0]][E[i][1]] = Value[i];
}
//  for( i = 0; i <= N; i++)
//  	for(j = 0; j <=  N; j++)
//  		cout << c[i][j] << endl;

int dist[LENGTH];
int prev[LENGTH];

bool s[Maxint];
int v = 1;

for(i = 1; i <= N; i++)
{
dist[i] = c[v][i];
s[i] = false;
if(dist[i]  == Maxint) prev[i] = 0;
else prev[i] = v;
}

dist[v] = 0;
s[v] = true;
for(i = 1; i < N; i++)
{
int temp = Maxint;
int u = v;
for(j = 1; j <= N; j++)
if((!s[j])&&(dist[j] < temp)) {u = j; temp = dist[j];}

s[u] = true;

for(j = 1; j <= N; j++)
if((!s[j]) && (c[u][j] < Maxint))
{
int newdist = dist[u] + c[u][j];
if(newdist < dist[j])
{
dist[j] = newdist;
prev[j] = u;
}
}
}
cout << "The shortest path: " <<endl;
for(i = 1; i <= N; i++)
{

if(i != 1)

cout << "1 -> " << i <<": " << dist[i] << endl;
}

system("PAUSE");
return EXIT_SUCCESS;
}