Cod sursa(job #2741208)

Utilizator GligarEsterabadeyan Hadi Gligar Data 15 aprilie 2021 18:14:02
Problema Cuplaj maxim in graf bipartit Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <fstream>
#include <vector>

using namespace std;

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

const int nmax=10000;

vector <int> g[2*nmax+1];

int u[2*nmax+1];

int v[2*nmax+1];

bool pairup(int x){
    if(u[x]==1){
        return 0;
    }else{
        u[x]=1;
        for(int i=0;i<int(g[x].size());i++){
            int xn=g[x][i];
            if(v[xn]==0){
                v[xn]=x;
                v[x]=xn;
                return 1;
            }else if(pairup(v[xn])==1){
                v[xn]=x;
                v[x]=xn;
                return 1;
            }
        }
    }
    return 0;
}

int main(){
    int n,n2,m;
    fin>>n>>n2>>m;
    for(int i=1;i<=m;i++){
        int x,y;
        fin>>x>>y;
        g[x].push_back(n+y);
        g[n+y].push_back(x);
    }
    bool ok=1;
    int sol=0;
    while(ok==1){
        ok=0;
        for(int i=1;i<=n+n2;i++){
            u[i]=0;
        }
        for(int i=1;i<=n;i++){
            if(v[i]==0){
                if(pairup(i)==1){
                    ok=1;
                    sol++;
                }
            }
        }
    }
    fout<<sol<<"\n";
    for(int i=1;i<=n;i++){
        if(v[i]!=0){
            fout<<i<<" "<<v[i]-n<<"\n";
        }
    }
    return 0;
}