Cod sursa(job #1739073)

Utilizator c0mradec0mrade c0mrade Data 8 august 2016 16:09:35
Problema Flux maxim Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.5 kb
#include<bits/stdc++.h>
using namespace std;
ifstream in("maxflow.in");
ofstream out("maxflow.out");

int N, M, x, y, z, flow, max_flow, nod;
int f[1111], c[1111][1111];
bitset<1111>viz;
vector<int> v[1111];
queue<int> q;

int bfs()
{
    memset(f,0,sizeof(f));
    viz.reset();
    q.push(1);
    viz[1] = 1;
    while(!q.empty())
    {
        int x = q.front();
        q.pop();
        viz[x] = 1;
        if(x != N)
            for(int i = 0; i < v[x].size(); ++i)
            {
                if(!viz[v[x][i]] && c[x][v[x][i]])
                {
                    viz[v[x][i]] = 1;
                    f[v[x][i]] = x;
                    q.push(v[x][i]);
                }
            }
    }
    return viz[N];
}

int main()
{
    in >> N >> M;
    for(int i = 0; i < M; ++i)
    {
        in >> x >> y >> z;
        v[x].push_back(y);
        v[y].push_back(x);
        c[x][y] = z;
    }

    while(bfs())
    {
        for(int i = 0; i < v[N].size(); ++i)
        {
            f[N] = v[N][i];
            nod = N;
            flow = 111111;
            while(nod != 1)
            {
                flow = min(flow, c[f[nod]][nod]);
                nod = f[nod];
            }
            nod = N;
            while(nod != 1)
            {
                c[f[nod]][nod] -= flow;
                c[nod][f[nod]] += flow;
                nod = f[nod];
            }
            max_flow += flow;
        }
    }
    out<<max_flow;
    return 0;
}