Cod sursa(job #2957873)

Utilizator Katherine456719Swan Katherine Katherine456719 Data 23 decembrie 2022 18:13:15
Problema Flux maxim Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.51 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

int n,m;
vector<vector<int>> muchii;
int cp[1005][1005];

int gaseste_drum(){
    vector<int> parinte(n+1,-1);
    queue <int>q;
    int node = 1;
    parinte[1] = 0;
    q.push(1);
    while(!q.empty()){
        node = q.front();
        q.pop();
        if(node != n) {
            for (auto i: muchii[node]) {
                if (parinte[i] == -1 and cp[node][i] > 0) {
                    q.push(i);
                    parinte[i] = node;
                }
            }
        }
        else {
            int flux = 9999999;
            while(node != 1){
                flux = min(flux,cp[parinte[node]][node]);
                node = parinte[node];
            }
            node = n;
            while(node != 1){
                cp[node][parinte[node]] +=flux;
                cp[parinte[node]][node] -=flux;
                node = parinte[node];
            }
            return flux;
        }
    }
    return 0;
}

int main(){
    ifstream fin("maxflow.in");
    ofstream fout("maxflow.out");
    fin >> n >> m;
    muchii.resize(n+1);
    while(m--){
        int x,y,cap;
        fin >> x >> y >> cap;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
        cp[x][y] = cap;
        cp[y][x] = 0;
    }
    int ans = 0;
    int x = gaseste_drum();
    while(x != 0){
        ans += x;
        x = gaseste_drum();
    }
    fout << ans;

    return 0;
};