链式前向星 + 堆优化$dijkstra$

1、不知道为什么 WA 了？

2、另外，我发现 greater< pair<int, int> > 即使没定义它也是默认排序 .first 吗？

3、我尝试自定义算子，但迷之CE？（调不来，本地没有报错，而是弹出一大堆乱码）

4、循环中的 ~i 是什么意思？

#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;
const int N = 1e5 + 10, inf = 0x3f3f3f3f;
struct edge
{
	int to, w, next;
}e[N];
int n, m, s, top, h[N], dist[N];
bool vis[N];
priority_queue< pii, vector<pii>, greater<pii> >  q;

void add(int x, int y, int w)
{
	e[++top] = {y, w, h[x]};
	h[x] = top;
}

void dijkstra()
{
	for (int i = 0; i <= n; i ++) dist[i] = inf;
	dist[s] = 0;
	q.push({0, s});
	while (!q.empty())
	{
		pii t = q.top();
		q.pop();
		int x = t.second;
		if (vis[x]) continue;
		vis[x] = true;
		for (int i = h[x]; i ; i = e[i].next)
		{
			int y = e[i].to, w = e[i].w;
			if (dist[x] + w < dist[y])
			{
				dist[y] = dist[x] + w;
				q.push({dist[y], y});
			}		
		}
	}
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	
	cin >> n >> m >> s;
	for (int i = 1; i <= m; i ++)
	{
		int x, y, w;
		cin >> x >> y >> w;
		add(x, y, w);
	}
	dijkstra();
	for (int i = 1; i <= n; i ++) cout << dist[i] << ' ';
	
	return 0;
}

struct cmp
{
	friend bool operator < (pii a, pii b)
	{
		if (a.first == b.first) return a.second < b.second;
		return a.first < b.first;
	}
};
priority_queue< pii, vector<pii>, cmp >  q;