最短路径

//最短路径 - Dijkstra算法 参数：图G、源点v
void Dijkstra(Graph G, int v)
{
    //初始化
    int n = G.vexnum;//n为图的顶点个数
    for (int i = 0; i < n; i++)
    {
        S[i] = false;
        D[i] = G.Edge[v][i];
        if (D[i] < INF)Pr[i] = v; //v与i连接，v为前驱
        else Pr[i] = -1;
    }
    S[v] = true;
    D[v] = 0;
    //初始化结束,求最短路径，并加入S集
    for (int i = 1; i < n; i++)
    {
        int min = INF;
        int temp;
        for (int w = 0; w < n; w++)
            if (!S[w] && D[w] < min) //某点temp未加入s集，且为当前最短路径
            {
                temp = w;
                min = D[w];
            }
        S[temp] = true;
    //更新从源点出发至其余点的最短路径 通过temp
        for (int w = 0; w < n; w++)
            if (!S[w] && D[temp] + G.Edge[temp][w] < D[w])
            {
                D[w] = D[temp] + G.Edge[temp][w];
                Pr[w] = temp;
            }
    }
}

//弗洛伊德基本代码
#include <bits/stdc++.h>
using namespace std;
int main()
{
    int e[401][401],l,k,i,j,n,m,t1,t2,t3;
    int inf=100000000; 
    int s;
    cin>>n>>m>>s>>l;
    for(i=1;i<=n;i++)
    for(j=1;j<=n;j++){
        if(i==j) e[i][j]=0;
        else e[i][j]=inf;
    }  
    for(i=1;i<=m;i++)
    {
        cin>>t1>>t2>>t3;
        e[t1][t2]=e[t2][t1]=t3;    
    }
    for(k=1;k<=n;k++)
    for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
    if(e[i][j]>e[i][k]+e[k][j])
        e[i][j]=e[i][k]+e[k][j];
    return 0;
}