蒟蒻求助，我这哪里错掉啦，改一整天了破防了，(内含我自己的思路和注释)

#include<bits/stdc++.h>
using namespace std;
const int N = 100000;

//链式前向星
struct zzz {
    int to;//指向的节点
    int val;//边权
    int nex;
}e[N];
int top, head[N];

void add(int x,int y,int z) {
    e[++top].to = y;
    e[top].val = z;
    e[top].nex = head[x];
    head[x] = top;
}
//ed of 链式前向星

//vis 数组和 dist 数组
int vis[N];
int dist[N];

//自定义的优先队列，里面存的是dist数组的下标
//小根堆，指dist[i]最小
struct cmp {
    bool operator()(int x, int y) {
        return dist[x] < dist[y];
    }
};
priority_queue<int, vector<int>, cmp> qe;

int main() {
    //读入n m s。
    int n, m, s;
    scanf("%d%d%d", &n, &m, &s);

   //依然读数据，因为无向图，所以加两次边
    for (int i = 1;i <= m; i++) {
        int x, y, z;
        scanf("%d%d%d", &x, &y, &z);
        add(x, y, z);
        add(y, x, z);
    }

   //dist 元素设为无穷大
    memset(dist, 127, sizeof(dist));
   //s节点置为初始节点入队且dist置为0
    dist[s] = 0;
    qe.push(s);

   //队列为空的时候说明都访问完毕
    while (!qe.empty()) {
    //将队首出队，访问相邻节点
        int a = qe.top();
        vis[a] = 1;
        qe.pop();

        for (int i = head[a];i;i = e[i].nex) {
        //若没有访问过
            if (vis[e[i].to] == 0) {
            //更新dist
                dist[e[i].to] = min(dist[e[i].to], dist[a] + e[i].val);
            //入队
                qe.push(e[i].to);
            }
        }
    }
   //逐个打印
    for (int i = 1;i <= n;i++) {
        printf("%d ", dist[i]);
    }
    return 0;
}