堆优化的dij【模板】

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
int head[1000005],n, m, cnt, ccnt;
long long dist[1000005],ans;
struct pot {
    int id;
    int val;
    bool operator<(const struct pot&aa)const {
        return val > aa.val;
    }
};
struct edge {
    int fr;
    int to;
    long long  v;
    int next;
}e[1000005];
void INIT() {
    memset(head, -1, sizeof(head));
    memset(dist, 0x3f3f3f3f, sizeof(dist));
    dist[1] = 0;
    cnt=0;
    ans = 0;
}
void adde(int xx, int yy,long long zz) {
    e[cnt].fr = xx;
    e[cnt].to = yy;
    e[cnt].v = zz;
    e[cnt].next = head[xx];
    head[xx] = cnt++;
}
void dij() {
    priority_queue<struct pot>pq;
    struct pot sta;
    sta.id = 1;
    sta.val = 0;
    pq.push(sta);
    while (!pq.empty()) {
        struct pot aa = pq.top(); pq.pop();
        if (dist[aa.id] < aa.val)continue;
        for (int i = head[aa.id]; i != -1; i = e[i].next) {
            if (dist[e[i].to] > dist[aa.id] + e[i].v) {
                dist[e[i].to] = dist[aa.id] + e[i].v;
                struct pot cc;
                cc.id = e[i].to;
                cc.val = dist[e[i].to];
                pq.push(cc);
            }
        }
    }
}
int main() {
    int t;
    scanf("%d",&t);
    while (t--) {
        INIT();
        scanf("%d%d", &n, &m);
        while (m--) {
            int x, y;
            long long z;
            scanf("%d%d%lld", &x, &y, &z);
            adde(x, y, z);
        }
        dij();
    }
    return 0;
}