用dijkstra和floyd都能过，用SPFA样例对了过不了啊，悬棺求助qwq

#include <queue>
#include <iostream>
#include <cstring>
using namespace std;
int a[1010][1010], n, m;
int d[1010];
void SPFA()
{
	bool f[1010] = {0};
	memset(d, 0x3f, sizeof(d));
	queue<int> q;
	q.push(1);
	d[1] = 0;
	while (!q.empty())
	{
		int u = q.front();
		f[u] = true;
		q.pop();
		for (int i = 1; i <= n; i++)
		{
			if (!f[i] && a[u][i] != 0x3f3f3f3f && d[u] + a[u][i] < d[i])
			{
				d[i] = d[u] + a[u][i];
				if (!f[i])
				{
					f[i] = true;
					q.push(i);
				}
			}
		}
		f[u] = false;
	}
}
void swap_()
{
	for (int i = 1; i <= n; i++)
	{
		for (int j = i + 1; j <= n; j++)
		{
			swap(a[i][j], a[j][i]);
		}
	}
}
int main()
{
	scanf("%d %d", &n, &m);
	memset(a, 0x3f, sizeof(a));
	for (int i = 1; i <= m; i++)
	{
		int u, v, l;
		scanf("%d %d %d", &u, &v, &l);
		a[u][v] = min(a[u][v], l);
	}
	int ans = 0;
	SPFA();
	for (int i = 1; i <= n; i++)
	{
		if (d[i] != 0x3f3f3f3f)
			ans += d[i];
	}
	swap_();
	SPFA();
	for (int i = 1; i <= n; i++)
	{
		if (d[i] != 0x3f3f3f3f)
			ans += d[i];
	}
	printf("%d", ans);
	return 0;
}

题目在这里p1629