好像能A一个点？帮忙调一下速度吧！第2个TLE了

#include <bits/stdc++.h>
using namespace std;
int t,n,m;
vector <int> b[500005];
int main()
{
	cin >> t;
	for (int w = 0;w < t;w++)
	{
		cin >> n >> m;
		for (int i = 0;i < m;i++)
		{
			int u,v;
			cin >> u >> v;
			b[u].push_back(v);
		}
		for (int i = 1;i <= n;i++)
		{
			sort(b[i].begin(),b[i].end());
			for (int j = 0;j < b[i].size();j++)
			{
				if (b[i][j] != i)
				{
					cout << b[i][j] << " ";		
				}
			}
			cout << endl;
		}
	}
	return 0;
}