计蒜客 - A1542

计蒜客 - A1542

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define fcio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define lowbit(x) (x&-x)
#define debug cout<<"What fuck!!"<
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn=1e3+10;
const int INF=0x3f3f3f3f;
const ll inf=0x3f3f3f3f3f3f3f3f;
int k,n,m;
int vis[maxn];
int man[maxn]; 
int love[maxn][maxn];
bool find(int x){
     
	for(int j=1;j<=n;++j){
     
		if(love[x][j]==1&&vis[j]==0){
     
			vis[j]=1;
			if(man[j]==0||find(man[j])){
     
				man[j]=x;//与男生j匹配的为女生j; 
				return true;
			}
		}
	}
	return false;
}
void floyd(){
     
	for(int k=1;k<=n;++k){
     
		for(int i=1;i<=n;++i){
     
			for(int j=1;j<=n;++j){
     
				if(love[i][k]&&love[k][j])
					love[i][j]=1;
			}
		}
	}
}
int main(){
     
	fcio;
	int T;
	while(cin>>T){
     
		while(T--){
     
			cin>>n>>m;
			memset(man,0,sizeof man);
			memset(love,0,sizeof love);
			int ans=0;
			for(int i=0;i<m;++i){
     
				int x,y;
				cin>>x>>y;
				love[x][y]=1;
			}
			floyd();
			for(int i=1;i<=n;++i){
     
				memset(vis,0,sizeof vis);
				if(find(i))
					ans++;
			}
			cout<<n-ans<<endl;
		}
	}
	return 0;
}