HDU 1874畅通工程续

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//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]);
	}
}