bzoj1191: [HNOI2006]超级英雄Hero

传送门
二分图匹配裸题。

#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<iostream> 
#define ll long long
using namespace std;
int n,m,x,y,ans;
int a[1005][1005],b[1005],lk[1005];
bool dfs(int x){
    for (int i=0;i<n;i++)
        if (!b[i]&&a[x][i]){
            b[i]=1;
            if (!lk[i]||dfs(lk[i])){
                lk[i]=x;
                return 1;
            }
        }
    return 0;
}
int main(){
    scanf("%d%d",&n,&m);
    for (int i=1;i<=m;i++){
        scanf("%d%d",&x,&y);
        a[i][x]=a[i][y]=1;
    }
    ans=0;
    for (int i=1;i<=m;i++){
        memset(b,0,sizeof(b));
        if (dfs(i)) ans++;
            else break;
    }
    printf("%d",ans);
    return 0;
}