rt，感觉自己写的很怪，但是能ac，有没有大佬改的更简洁一点

#include <bits/stdc++.h>
#define int long long

using std::cin;
using std::cout;
const int N = 1e5 + 5;
const int M = 2e5 + 5;
int dis[N], cnt, n, m, s;
bool vis[N];
struct edge {
	int v, w;
	edge* next;
	edge* prev;
	edge() {
		next = prev = nullptr;
	}
};
edge* head[N];
void add_edge(int u, int v, int w) {
	if (!head[u]) {
		head[u] = new edge();
		head[u] -> v = v;
		head[u] -> w = w;
	} else {
		head[u] -> prev = new edge();
		head[u] -> prev -> v = v;
		head[u] -> prev -> w = w;
		head[u] -> prev -> next = head[u];
		head[u] = head[u] -> prev;
	}
}

struct node {
	int dis, pos;
	bool operator< (const node& x) const {
		return dis > x.dis;
	}
};
std::priority_queue<node> q;
void dijkstra(int s) {
	memset(dis, 0x3f, sizeof(dis));
	dis[s] = 0;
	q.push({0, s});
	while (!q.empty()) {
		int u = q.top().pos;
		q.pop();
		if (vis[u])
			continue;
		vis[u] = 1;
		for (edge* e = head[u]; e; e = e -> next) {
			int v = e -> v, w = e -> w;
			if (dis[v] > dis[u] + w) {
				dis[v] = dis[u] + w;
				q.push({dis[v], v});
			}
		}
	}
}
signed main(void) {
	cin >> n >> m >> s;
	for (int i = 1; i <= m; i++) {
		int u, v, w;
		cin >> u >> v >> w;
		add_edge(u, v, w);
	}
	dijkstra(s);
	for (int i = 1; i <= n; i++)
		cout << dis[i] << ' ';
	return 0;
}