HDU 1874畅通工程续

//重边
//双向图
//if 忘记大括号
#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;

const int maxn = 2e2+3;
const int INF = 0x3f3f3f3f;

int mp[maxn][maxn];
int vis[maxn];
int dis[maxn];

int main (){
int m,n;
int a,b,x;
int s,t;
int ans;
while (scanf("%d%d", &n, &m) != EOF){

memset(mp,0x3f,sizeof(mp));
memset(vis,0,sizeof(vis));
memset(dis,0x3f,sizeof(dis));
for (int i = 0; i < m; i++){
scanf("%d%d%d", &a, &b, &x);
if (x < mp[a][b]){
mp[a][b] = x;
mp[b][a] = x;
}

}
scanf("%d%d", &s, &t);
for (int i = 0; i < n; i++){
mp[i][i] = 0;
}
queue<int> que;
while (!que.empty()){
que.pop() ;
}
dis[s] = 0; vis[s] = 1;
que.push(s);
while (!que.empty() ){
int u = que.front() ;
que.pop() ;
vis[u] = 0;
for (int i = 0; i < n; i++){
if (dis[i] > dis[u] + mp[u][i]){
dis[i] = dis[u] + mp[u][i];
if (!vis[i]){
vis[i] = 1;
que.push(i);
}
}
}
}
if (dis[t] >= INF){
printf("-1\n");
}
else printf("%d\n",dis[t]);
}
}