#include<cstdio>
#include<algorithm>


const	int		maxn=301;

struct	mnode
{
	int		v;
	mnode	*next;
};

mnode	mem[maxn];
int		mtail;

mnode	*graph[maxn];
int		n,m;

int		matchy[maxn];
bool	marked[maxn];

void	gadd(int	u,int	v)
{
	mtail++;
	mem[mtail].v=v;
	mem[mtail].next=graph[u];
	graph[u]=&mem[mtail];
}
void	init()
{
	int		i,t,v;
	
	mtail=0;
	memset(graph,0,sizeof(graph));
	scanf("%d %d\n",&n,&m);
	memset(matchy,0,sizeof(matchy));
	memset(marked,0,sizeof(marked));
	
	for (i=1;i<=n;i++)
	{
		scanf("%d",&t);
		while (t--)
		{
			scanf("%d",&v);
			gadd(i,v);
		}
		scanf("\n");
	}
	
}

bool	search(int	v)
{
	mnode		*iter;
	
	if (marked[v])
		return(false);
	
	marked[v]=true;
	for (iter=graph[v];iter;iter=iter->next)
		if ((!matchy[iter->v])||(search(matchy[iter->v])))
		{
			matchy[iter->v]=v;
			return(true);
		}
	return(false);
}
void	starmain()
{
	int		i;
	
	for (i=1;i<=n;i++)
	{
		memset(marked,0,sizeof(marked));		
		if (!search(i))
		{
			printf("NO\n");
			return;
		}
	}
	printf("YES\n");
	
}
int		main()
{
	int		t;
	
//	freopen("c:\\in.txt","r",stdin);
	
	scanf("%d\n",&t);
	while (t--)
	{
		init();
		starmain();
	}
	return(0);
}

• RPWT ^_^ (1442) gaosimeng 2007-08-14 21:20:00