Cod sursa(job #3301968)

Utilizator iulia_morariuIuli Morariu iulia_morariu Data 1 iulie 2025 19:10:13
Problema Cuplaj maxim in graf bipartit Scor 12
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.43 kb
#include <algorithm>
#include <iostream>
#include <fstream>
#include <climits>
#include <vector>
#include <stack>
#include <cmath>
// #include <bits/stdc++.h>
#define in  fin
#define out fout

using namespace std;

ifstream fin("cuplaj.in");
ofstream fout("cuplaj.out");

vector<int> g[20001];
int cuplaj[20001]; // cuplaj[i] = cu cine e cuplat i
bool mr[20001];

bool pair_up(int nod){
    // cout << "nod = " << nod << endl;
    if(mr[nod]) return 0;
    mr[nod] = 1;
    for(const int &cop : g[nod]){
        if(!cuplaj[cop]){
            cuplaj[cop] = nod;
            cuplaj[nod] = cop;
            return 1;
        }
    }

    for(const int &cop : g[nod]){
        if(cuplaj[cop] != nod && pair_up( cuplaj[cop] )){
            cuplaj[cop] = nod;
            cuplaj[nod] = cop;
            return 1;
        }
    }
    return 0;
}

signed main(){
    ios_base::sync_with_stdio(false);
    in.tie(NULL);

    int n, m, E; in >> n >> m >> E;
    for(int ii = 0; ii < E; ii++){
        int a, b; in >> a >> b;
        // sa fie in stange 1, 2, ... , n si la dreapta n + 1, n + 2, ... n + m
        g[a].push_back(b + n);
    } 

    bool mai_bine = 1;
    int sol = 0;
    while(mai_bine){
        mai_bine = 0;
        for(int i = 1; i <= n; i++) mr[i] = 0;
        for(int i = 1; i <= n; i++){
            if(!mr[i] && pair_up(i)){
                mai_bine = 1;
                sol++;
            }
        }
    }

    out << sol << '\n';

    return 0;
}