90 pts WA on #9求调

#include <bits/stdc++.h>
using namespace std;
int n, m, ans;
vector <int> p[100005];
bool visited[100005];
int match[100005], ansg[100005];
bool dfs(int u)
{
	for(auto v : p[u])
	{
		if(!visited[v])
		{
			visited[v] = 1;
			if(!match[v] || dfs(match[v]))
			{
				match[v] = u;
				ansg[u] = v;
	//			cout << u << ' ' << v << '\n'; 
				return 1;
			}
		}else{
			continue;
		}
	}
	return 0;
}
int main()
{
	cin >> n >> m;
	for(int i = 1;i <= m; i++)
	{
		int u, v;
		cin >> u >> v;
		p[i].push_back(v);
		if(u!=v)p[i].push_back(u);
	}
	for(int i = 1;i <= m; i++)
	{
		if(dfs(i))
			ans++;
		else 
			break;
			
		for(int i = 1;i <= 100001; i++)
			visited[i] = 0;
	}
	
	cout << ans << '\n';
	for(int i = 1;i <= ans; i++)
	{
		cout << ansg[i] << '\n';
	}
	return 0;
}