hdu 1083 Courses(二分图最大匹配)

#include <cstdio>
#include <cstring>

const int MAXN = 500;
int g[MAXN][MAXN];
int linker[MAXN];
bool used[MAXN];
int p,n;

bool dfs(int u)
{
for(int v = 1;v <= n; ++v)
{
if(g[u][v] && !used[v])
{
used[v] = true;
if(linker[v] == -1 || dfs(linker[v]))
{
linker[v] = u;
return true;
}
}
}
return false;
}

int hungary()
{
int res = 0;
memset(linker,-1,sizeof(linker));
for(int i = 1; i <= p; ++i)
{
memset(used,false,sizeof(used));
if(dfs(i)) ++res;
}
return res;
}

int main()
{
int t,a,b;
scanf("%d",&t);
while(t--)
{
memset(g,0,sizeof(g));
scanf("%d %d",&p,&n);
for(int i = 1; i <= p; ++i)
{
scanf("%d",&a);
while(a--)
{
scanf("%d",&b);
g[i][b] = 1;
}
}
if(hungary() == p)
printf("YES\n");
else
printf("NO\n");
}
return 0;
}