https://vjudge.net/problem/17632/origin

上代码

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<functional>
#include<queue>
using namespace std;
const int maxn=1e3+5;
const int inf=0x3f3f3f3f;
typedef pair<int,int> P;
vector<P> G[maxn];
int d[maxn];
void init(int n){
    for(int i=0;i<n;i++)d[i]=inf;
    for(int i=0;i<n;i++)G[i].clear();
}
void dijkstra(int s){
    priority_queue<P,vector<P>,greater<P> >Q;
    d[s]=0;
    Q.push(make_pair(d[s],s));
    while(!Q.empty()){
        int now=Q.top().second;
        Q.pop();
        for(int i=0;i<G[now].size();i++){
            int v=G[now][i].first;
            if(d[v]>d[now]+G[now][i].second){
                d[v]=d[now]+G[now][i].second;
                Q.push(make_pair(d[v],v));
            }
        }
    }
}
int main(){
    int n,m;
    while(cin>>n>>m){
        init(n);
        for(int i=1;i<=m;i++){
            int x,y,v;
            cin>>x>>y>>v;
            G[x].push_back(make_pair(y,v));
            G[y].push_back(make_pair(x,v));
        }
        int s,t;
        cin>>s>>t;
        dijkstra(s);
        if(d[t]==inf)cout<<"-1"<<endl;
        else cout<<d[t]<<endl;
    }
    return 0;
}