Cod sursa(job #1988646)

Utilizator flaviu_2001Craciun Ioan-Flaviu flaviu_2001 Data 3 iunie 2017 23:18:38
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.34 kb
#include <fstream>
#include <vector>
#include <cstring>
#include <queue>

using namespace std;

vector<int> v[1005];
int c[1005][1005], f[1005][1005], n, m, vis[1005], tt[1005];

bool bfs()
{
    memset(vis, 0, sizeof(vis));
    queue<int> q;
    q.push(1);
    vis[1] = 1;
    while(!q.empty()){
        int nod = q.front();
        q.pop();
        for (int j = 0; j < v[nod].size(); ++j){
            int x = v[nod][j];
            if(c[nod][x] == f[nod][x] || vis[x])
                continue;
            vis[x] = 1;
            q.push(x);
            tt[x] = nod;
            if(x == n)
                return 1;
        }
    }
    return 0;
}

int abs(int x)
{
    return x >= 0 ? x : -x;
}

int main()
{
    ifstream fin ("maxflow.in");
    ofstream fout ("maxflow.out");
    fin >> n >> m;
    while(m--){
        int x, y, z;
        fin >> x >> y >> z;
        v[x].push_back(y);
        v[y].push_back(x);
        c[x][y] = z;
    }
    int flow, fmin;
    for (flow = 0; bfs(); flow += fmin){
        fmin = 1000000000;
        for (int nod = n; nod != 1; nod = tt[nod])
            fmin = min(fmin, c[tt[nod]][nod] - f[tt[nod]][nod]);
        for (int nod = n; nod != 1; nod = tt[nod]){
            f[tt[nod]][nod] += fmin;
            f[nod][tt[nod]] -= fmin;
        }
    }
    fout << flow << "\n";
    fin.close();
    fout.close();
    return 0;
}