最大匹配问题;
直接代码了,
#include<iostream>
#include <vector>
#include <stdio.h>
using namespace std;
#define MAXN 350
vector <int> map[MAXN];
int path[MAXN];
int vst[MAXN];
int n,m,k;//n,m??????????С
//int t;
bool dfs(int v)
{
int i;
for(i=0;i<map[v].size();i++)
{
if(!vst[map[v][i]])
{
vst[map[v][i]]=1;
if(path[map[v][i]]==-1||dfs(path[map[v][i]]))
{
path[map[v][i]]=v;
return true;
}
}
}
return false;
}
int hungary()
{
int i;
int cnt=0;
memset(path,-1,sizeof(path));
for(i=1;i<=n;i++)
{
memset(vst,0,sizeof(vst));
if(dfs(i))
cnt++;
}
return cnt;
}
int main()
{
int t;
cin>>t;
int key;
while (t--)
{
for (int q=0; q<MAXN; ++q)
map[q].clear();
cin>>n>>m;
for (int i=1; i<=n; ++i)
{
cin>>k;
for (int j=0; j<k; ++j)
{
cin>>key;
map[i].push_back(key);
}
}
if ( hungary()==n)
cout<<"YES\n";
else
cout<<"NO\n";
}
}