hdoj1151

Problem : 1151 ( Air Raid )     Judge Status : Accepted
RunId : 2873274    Language : G++    Author : huwenbiao
Code Render Status : Rendered By HDOJ G++ Code Render Version 0.01 Beta

/***************************************************************\
 *Author:Hu Wenbiao
 *Created Time: Wed 25 Aug 2010 05:06:48 PM CST
 *File Name: d.cpp
 *Description:最小路径覆盖
\***************************************************************/
//*========================*Head File*========================*\\

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
/*----------------------*Global Variable*----------------------*/
int T,n,num,a,b,lx[121],ly[121];
bool G[121][121],mark[121];
//*=======================*Main Program*=======================*//
using namespace std;

int path(int u){
    for(int v=1;v<=n;v++){
        if(G[u][v]&&!mark[v]){
            mark[v]=true;
            if(ly[v]==-1||path(ly[v])){
                lx[u]=v;
                ly[v]=u;
                return 1;
            }
        }
    }
    return 0;
}
int max_match(){
    memset(lx,-1,sizeof(lx));
    memset(ly,-1,sizeof(ly));
    int sum=0;
    for(int i=1;i<=n;i++){
        if(lx[i]==-1){
            memset(mark,false,sizeof(mark));
            sum+=path(i);
        }
    }
    return sum;
}
int main(){
    //freopen("input","r",stdin);
    scanf("%d",&T);
    while(T--){
        scanf("%d%d",&n,&num);
        memset(G,0,sizeof(G));
        while(num--){
            scanf("%d%d",&a,&b);
            G[a][b]=true;
        }
        printf("%d\n",n-max_match());
    }
}