【模板】单源最短路径（Dijkstra + 堆优化）

#include <iostream>
#include <queue>
using namespace std;
const int inf = 2147483647;
const int MAXX = 2e5 + 11;
int n,m,s,cnt;
int dis[MAXX];
int to[MAXX],nxt[MAXX],val[MAXX],h[MAXX];
bool vis[MAXX];
struct node{
    int v,w;
    friend bool operator < (node a,node b){
        return a.w > b.w;
    }
} tmp;
priority_queue <node> q;
void add(int u,int v,int w){
    cnt ++;
    to[cnt] = v;
    val[cnt] = w;
    nxt[cnt] = h[u];
    h[u] = cnt;
}
void dijkstra(){
    for (int i = 1;i <= n;i ++){
        dis[i] = inf;
    }
    dis[s] = 0;
    tmp.v = s,tmp.w = 0;
    q.push(tmp);
    while(!q.empty()){
        int u = q.top().v;
        q.pop();
        if (vis[u]){
            continue;
        }
        vis[u] = 1;
        for (int i = h[u];i;i = nxt[i]){
            if (dis[to[i]] > (long long)dis[u] + val[i]){
                dis[to[i]] = dis[u] + val[i];
                tmp.w = dis[to[i]];
                tmp.v = to[i];
                q.push(tmp);
            }
        }
    }
}
signed main(){
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    cin >> n >> m >> s;
    for (int i  = 1,u,v,w;i <= m;i ++){
        cin >> u >> v >> w;
        add(u,v,w);
    }
    dijkstra();
    for (int i = 1;i <= n;i ++){
        cout << dis[i] << " ";
    }
    return 0;
}