求条

#include <bits/stdc++.h>
using namespace std;
int n,m,low[150],dfn[150],father[150],idx,cnt;
vector <int> q[150];
pair <int,int> gb[5000];
void tarjan(int u,int fa)
{
	father[u] = fa;
	low[u] = dfn[u] = ++idx;
	for (int i = 0;i < q[u].size();i++)
	{
		int v = q[u][i];
		if (!dfn[v])
		{
			tarjan(v,u);
		}
		low[u] = min(low[u],low[v]);
		if (low[v] > dfn[u])
		{
			gb[cnt].first = min(u,v);
			gb[cnt].second = max(u,v);
			cnt++;
		}
		else if (v != fa)
		{
			low[u] = min(low[u], dfn[v]);
		}
	}
}
int main()
{
	cin >> n >> m;
	for (int i = 0;i < m;i++)
	{
		int a,b;
		cin >> a >> b;
		q[a].push_back(b);
		q[b].push_back(a);
	}
	for (int i = 1;i <= n;i++)
	{
		if (!dfn[i])
		{
			tarjan(i,-1);
		}
	}
	sort(gb,gb + cnt);
	for (int i = 0;i < cnt;i++)
	{
		cout << gb[i].first << ' ' <<  gb[i].second << endl;
	}
	return 0;
}