Cod sursa(job #2884063)

Utilizator hurjui12AlexandruHurjui Alexandru-Mihai hurjui12Alexandru Data 2 aprilie 2022 12:48:27
Problema Flux maxim Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.36 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

vector <int> v[1001];
int c[1001][1001];

int bfsflux (int s, int t, int p[])
{
    int i, na, nv, flux[1001] = {};
    queue <int> q;

    flux[s] = 1<<30;
    q.push (s);

    while (q.empty() == 0)
    {
        na = q.front();
        q.pop();

        for (i = 0; i<v[na].size(); i++)
            if (flux[v[na][i]] == 0 && c[na][v[na][i]] != 0)
            {
                flux[v[na][i]] = min (flux[na], c[na][v[na][i]]);
                p[v[na][i]] = na;

                if (v[na][i] == t)
                    return flux[t];

                q.push (v[na][i]);
            }
    }

    return 0;
}

int main()
{
    int p[1001];
    int n, m, i, x, y, z;
    int flux, rasp;

    fin >> n >> m;
    for (i = 1; i<=m; i++)
    {
        fin >> x >> y >> z;
        v[x].push_back (y);
        v[y].push_back (x);

        c[x][y] += z;
    }

    rasp = 0;
    do
    {
        flux = bfsflux (1, n, p);
        rasp += flux;

        x = n;
        while (x != 1)
        {
            y = p[x];
            c[y][x] -= flux;
            c[x][y] += flux;
            x = y;
        }

    } while (flux != 0);

    fout << rasp;
    return 0;
}