Cod sursa(job #3329928)

Utilizator adistancu10Stancu Adrian adistancu10 Data 16 decembrie 2025 14:41:10
Problema Flux maxim Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.68 kb
#include <bits/stdc++.h>

using namespace std;

const int NMAX = 1e3;
int capacitate[NMAX + 1][NMAX + 1], flux[NMAX + 1][NMAX + 1];
int vis[NMAX + 1], p[NMAX + 1];
vector<int> G[NMAXX + 1];
int n,m;

int bfs (int s, int d){
    for(int i = 1; i <= n; i++){
        vis[i] = 0;
        p[i] = 0;
    }

    queue<int> q;
    q.push(s);
    vis[s] = 1;
    while(!q.empty()){
        int nod = q.front();
        q.pop();
        for(auto vecin : G[nod]){
            if(!vis[vecin] && capatitate[nod][vecin] - flux[nod][vecin] > 0){
                vis[vecin] = 1;
                q.push(vecin);
                p[vecin] = nod;
            }
        }

    }

    if(vis[d] == 0){
        return 0;
    }
    vector<int> path;
    while(d != 0){
        path.push_back(d);
        d = p[d];
    }

    reverse(path.begin(), path.end());
    int flow = 1e9;
    for(int i = 0; i < path.size() - 1; i++){
        int x = path[i];
        int y = path[i + 1];
        flow = min(flow, capacitate[x][y] - flux[x][y]);
    }
    for(int i = 0; i < path.size() - 1; i++){
        int x = path[i];
        int y = path[i + 1];
        flux[x][y] += flow;
        flux[y][x] -= flow;
    }

    return flow;
}

int main(){
    ifstream cin("maxflow.in");
    ofstream cout("maxflow.out");
    cin >> n >> m;
    for(int i = 1; i <= m; i++){
        int x, y, c;
        cin >> x >> y >> c;
        capacitate[x][y] = c;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    int maxflow = 0;
    while(true){
        int flow = bfs(1, n);
        if(flow == 0){
            break;
        }
        maxflow += flow;
    }

    cout << maxflow;
}