51nod 2006 飛行員配對(二分圖最大比對，)

​​題目​​

分析

#include <bits/stdc++.h>
#pragma GCC diagnostic error "-std=c++11"
#define d(x) cout << (x) << endl
#define INF 0x3f3f3f3f
#define eps 1e-8
using namespace std;
typedef long long ll;
const int mod = 1e9 + 7;
const int N = 1e2 + 10;

int n, m, q, p;
vector<int> g[N];
int vis[N];     //Y點集是否通路過
int link[N];    //linl[y]=x  Y點集與x連接配接

int find(int x)
{
    for(auto y : g[x]){
        if(!vis[y]){
            vis[y] = 1;
            if(link[y] == -1 || find(link[y])){
                link[y] = x;
                return 1;
            }
        }
    }
    return 0;
}

int main()
{
    scanf("%d%d", &m, &n);
    while(~scanf("%d%d", &p, &q)){
        if(q == -1 && p == -1)
            break;
        g[p].push_back(q);
        g[q].push_back(p);
    }
    memset(link, -1, sizeof(link));
    int ans = 0;
    for (int i = 1; i <= m; i++){
        memset(vis, 0, sizeof(vis));
        if(find(i))
            ans++;
    }
    printf("%d\n", ans);
    return 0;
}