匈牙利算法模板

代码

\(m\)为左端点 , \(n\)为右端点 , \(e\)为边数

#include<bits/stdc++.h>
using namespace std;
const int N = 5e4+10;
inline int read() {
    int ans = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-')f = -1;
        ch = getchar();
    }
    while (ch <= '9' && ch >= '0') {
        ans = ans * 10 + ch - '0';
        ch = getchar();
    }
    return ans * f;
}
vector<int> ed[N];
bool vis[N];
int n,m,e,u,v,ans , match[N];
bool dfs(int u) {
    for (auto e : ed[u]) {
        if (vis[e])
            continue;
        vis[e] = true;
        if (!match[e] || dfs(match[e])) {
            match[e] = u;
            return true;
        }
    }
    return false;
}
int main() {
    n =read() , m=read() , e=read();
    for (int i =1;i<= e; i++) {
        u =read(),v=read();
        ed[u].push_back(n+v);
    }
    for (int i = 1; i<= n;i++) {
        memset(vis,false,sizeof vis);
        if (dfs(i))ans++;
    }
    cout<<ans;
    return 0;
}