Cod sursa(job #3294581)

Utilizator alecu2008Alecu Alexandru alecu2008 Data 25 aprilie 2025 19:07:07
Problema Flux maxim Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <iostream>
#include <bits/stdc++.h>
using namespace std;

#define cin fin
#define cout fout


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

const int nmax=1024,inf=0x3f3f3f3f;
int n,m,x,y,z,nod,nod2;
vector<vector<int> > graf;
int c[nmax][nmax],TT[nmax],f[nmax][nmax];
bitset<nmax> vas;
queue<int> cd;

int bf(){
while(!cd.empty())
    cd.pop();
cd.push(1);
vas.reset();
vas[1]=1;
while(!cd.empty()){
    nod2=cd.front();
    //cout<<nod2<<' ';
    cd.pop();
    for(int i:graf[nod2]){
        if(!vas[i]&&c[nod2][i]>f[nod2][i]){
            cd.push(i);
            vas[i]=1;
            TT[i]=nod2;
            if(i==n)return 1;
        }
    }
}
return 0;
}







int main()
{
    int flow,fmin;
    cin>>n>>m;
    graf.assign(n+1,vector<int>());
    for(int i=0;i<m;i++){
        fin>>x>>y>>z;
        c[x][y]+=z;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(flow=0;bf();flow+=fmin){
        //cout<<'\n';
        fmin=inf;
        for(nod=n;nod!=1;nod=TT[nod]){
            fmin=min(fmin,c[TT[nod]][nod]-f[TT[nod]][nod]);
        }
        for(nod=n;nod!=1;nod=TT[nod]){
            f[TT[nod]][nod]+=fmin;
            f[nod][TT[nod]]-=fmin;
        }
        //cout<<fmin;
    }
    cout<<flow;
    return 0;
}