$P5318$

#include<bits/stdc++.h>
using namespace std;
bool vis[10010];
queue <int> q;
struct t
{
	vector <int> l;
}a[10010];
void dfs(int n)
{	cout<<n<<" ";
	vis[n]=1;
	if(a[n].l.size()==0)return ;
	for(int i=0;i<=a[n].l.size()-1;i++)
	{
		if(vis[a[n].l[i]]==0)dfs(a[n].l[i]);
	}
}
void bfs()
{
	q.push(1);
	cout<<1<<" ";
	vis[1]=1;
	while(!q.empty())
	{
		if(a[q.front()].l.size()==0)
		{
			q.pop();
			continue;
		}
		for(int i=0;i<=a[q.front()].l.size()-1;i++)
		{
			if(vis[a[q.front()].l[i]]==0)
			{
				cout<<a[q.front()].l[i]<<" ";
				vis[a[q.front()].l[i]]=1;
				q.push(a[q.front()].l[i]);
			}
		}
		q.pop();
	}
}
int main()
{
	int n,m;
	cin>>n>>m;
	for(int i=1;i<=m;i++)
	{
		int u,v;
		cin>>u>>v;
		a[u].l.push_back(v);
	}
	dfs(1);
	cout<<endl;
	memset(vis,0,sizeof(vis));
	bfs();
}

为什么错？