这是代码：

#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int read() {
	int f = 1, x = 0;
	char c = getchar();
	while (c < '0' || c > '9') {
		if (c == '-')f = -1;
		c = getchar();
	}
	while (c >= '0' && c <= '9') {
		x = x * 10 + c - '0';
		c = getchar();
	}
	return f * x;
}
void write(long long x) {
	if (x < 0) {
		putchar('-');
		x = -x;
	}
	if (x > 9)write(x / 10);
	putchar(x % 10 + '0');
}
int n = read(), m = read(), s = read(), l, tot, head[N];
long long dis[N];
struct Node {
	int to, nxt, w;
} a[N << 1];
struct node {
	int pos;
	long long w;
	bool operator <(const node& c)const {
		return c.w < w;
	}
};
void add(int u, int v, int w) {
	a[++tot].to = v;
	a[tot].w = w;
	a[tot].nxt = head[u];
	head[u] = tot;
}
void dijkstra() {
	dis[s] = 0;
	priority_queue<node>q;
	q.push({
		s, 0
	});
	while (!q.empty()) {
		node now = q.top();
		q.pop();
		int u = now.pos;
		if (now.w != dis[u])continue;
		for (int i = head[u]; i; i = a[i].nxt) {
			int v = a[i].to, w = a[i].w;
			if (dis[v] > dis[u] + w) {
				dis[v] = dis[u] + w;
				q.push({
					v, dis[v]
				});
			}
		}
	}
}
int main() {
	for (int i = 1; i <= m; i++) {
		//int u = read(), v = read(), w = read();
		add(read(), read(), read());
	}
	memset(dis, 0x3f3f3f3f, sizeof(dis));
	dijkstra();
	for (int i = 1; i <= n; i++) {
		write(dis[i]);
		putchar(' ');
	}
	return 0;
}

在建图时我直接传快读的值连样例都过不了，改掉就 A 了。为什么不能这么用快读啊。