bzoj1191 HNOI2006 超级英雄

/*
Author: JDD
PROG: bzoj1191 超级英雄
DATE: 2015.9.24 
*/

#include <cstdio>
#include <cstring> 
#define REP(i, s, n) for(int i = s; i <= n; i ++)
#define REP_(i, s, n) for(int i = n; i >= s; i --)
#define MAX_N 1005

using namespace std;

int n, m;
int link[MAX_N][MAX_N], G[MAX_N];
bool used[MAX_N];

void init()
{
    scanf("%d%d", &n, &m);
    memset(link, 0, sizeof(link));
    memset(G, 0, sizeof(G));
    REP(i, 1, m){
        int x, y; scanf("%d%d", &x, &y),
        x ++, y ++;
        link[i][x] = 1; link[i][y] = 1;
    }
}

bool find(int x)
{
    REP(j, 1, n){    
        if (link[x][j] == true && used[j] == false){
            used[j]=1;
            if (G[j] == 0 || find(G[j])){ 
                G[j] = x;
                return true;
            }
        }
    }
    return false;
}

void doit()
{
    int ans = 0;
    REP(i, 1, m){
        memset(used, 0, sizeof(used));
        if(find(i)) ans ++;
            else break;
    }
    printf("%d\n", ans);
}

int main()
{
    init();
    doit();
    return 0;
}