Cod sursa(job #2959217)

Utilizator vlad082002Ciocoiu Vlad vlad082002 Data 30 decembrie 2022 10:45:13
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <bits/stdc++.h>
using namespace std;

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

int n, c[1005][1005], f[1005][1005], t[1005], m;
vector<int> g[1005];
bool v[1005];

bool bfs() {
    for(int i = 1; i <= n; i++) v[i] = false;
    queue<int> q;
    q.push(1);
    v[1] = true;
    while(!q.empty()) {
        int cur = q.front();
        q.pop();

        for(auto next: g[cur])
            if(!v[next] && c[cur][next] > f[cur][next]) {
                t[next] = cur;
                v[next] = true;
                if(next == n) return true;

                q.push(next);
            }
    }
    return false;
}

int main() {
    fin >> n >> m;
    while(m--) {
        int u, v, w;
        fin >> u >> v >> w;
        g[u].push_back(v);
        g[v].push_back(u);
        c[u][v] = w;
    }

    int flow = 0, fmin;
    for(; bfs(); ) {
        for(auto next: g[n]) {
            if(!v[next] || c[next][n] <= f[next][n]) continue;
            t[n] = next;

            fmin = 2e9;
            for(int i = n; i != 1; i = t[i])
                fmin = min(fmin, c[t[i]][i]-f[t[i]][i]);

            for(int i = n; i != 1; i = t[i]) {
                f[t[i]][i] += fmin;
                f[i][t[i]] -= fmin;
            }
            flow += fmin;
        }
    }
    fout << flow << '\n';
}