hdu 1083 Courses

#include<iostream>
#include<cstring>
#define maxn 305
using namespace std;
int c,s;
int rem[maxn][maxn];
int visit[maxn],map[maxn];
int dfs(int x)
{
for(int i=1;i<=s;i++)
{
if(rem[x][i]&&!visit[i])
{
visit[i]=1;
if(!map[i]||dfs(map[i]))
{
map[i]=x;
return 1;
}
}
}
return 0;
}
int main()
{
int t;
cin>>t;
while(t--)
{
memset(rem,0,sizeof(rem));
memset(map,0,sizeof(map));
cin>>c>>s;
for(int i=1;i<=c;i++)
{
int x,y;
cin>>x;
while(x--)
{
cin>>y;
rem[i][y]=1;
}
}
int sum=0;
for(int i=1;i<=c;i++)
{
memset(visit,0,sizeof(visit));
if(dfs(i)) sum++;
}
if(sum==c) cout<<"YES"<<endl;
else cout<<"NO"<<endl;
}
return 0;
}