Cod sursa(job #880955)

Utilizator danutbodbodnariuc danut danutbod Data 17 februarie 2013 15:53:24
Problema Flux maxim Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 3.02 kb
#include <fstream>
#include<cstring>
#include <vector>

using namespace std;

#define NMAX 1024
#define pb push_back
#define sz size()
#define mp make_pair
#define INF 0x3f3f3f3f

int C[NMAX][NMAX];
int F[NMAX][NMAX];
int TT[NMAX];
vector<int> G[NMAX];
int N, M;
int cd[NMAX];
int viz[NMAX];

int BF()
{
    int i, j, nod, V;

    cd[0] = 1;
    cd[1] = 1;
    memset(viz, 0, sizeof(viz));
    viz[1] = 1;

    for (i = 1; i <= cd[0]; i++)
    {
        nod = cd[i];
        for (j = 0; j < G[nod].sz; j++)
            {
                V = G[nod][j];
                if (C[nod][V] == F[nod][V] || viz[V]) continue;
                viz[V] = 1;
                cd[ ++cd[0] ] = V;
                TT[V] = nod;
                if (V == N) return 1;
            }
    }

    return 0;
}

int main()
{
    fstream f("maxflow.in");
    ofstream g("maxflow.out");

    int i, flow, fmin, x, y, z, nod;

    f>>N>>M;

    for (i = 1; i <= M; i++)
    {
        f>>x>>y>>z;
        C[x][y] += z;
        G[x].pb(y);
        G[y].pb(x);
    }

    for (flow = 0; BF(); flow += fmin)
    {
        fmin = INF;
        for (nod = N; nod != 1; nod = TT[nod])
            fmin = min(fmin, C[ TT[nod] ][nod] - F[ TT[nod] ][nod]);
        for (nod = N; nod != 1; nod = TT[nod])
        {
            F[ TT[nod] ][nod] += fmin;
            F[nod][ TT[nod] ] -= fmin;
        }
    }

    g<<flow;
    return 0;
}
//#include <fstream>
//#include<cstring>
//#include <vector>
//using namespace std;
//#define NMAX 1024
//#define pb push_back
//#define sz size()
//#define mp make_pair
//#define INF 0x3f3f3f3f
//ifstream f("maxflow.in");
//ofstream g("maxflow.out");
//
//int C[NMAX][NMAX];
//int F[NMAX][NMAX];
//int TT[NMAX];
//vector<int> G[NMAX];
//int N, M;
//int cd[NMAX];
//int viz[NMAX];
//
//int BF()
//{
//    int i, j, nod, V;
//
//    cd[0] = 1;
//    cd[1] = 1;
//    memset(viz, 0, sizeof(viz));
//    viz[1] = 1;
//
//    for (i = 1; i <= cd[0]; i++)
//    {
//        nod = cd[i];
//        for (j = 0; j < G[nod].sz; j++)
//            {
//                V = G[nod][j];
//                if (C[nod][V] == F[nod][V] || viz[V]) continue;
//                viz[V] = 1;
//                cd[ ++cd[0] ] = V;
//                TT[V] = nod;
//                if (V == N) return 1;
//            }
//    }
//
//    return 0;
//}
//
//int main()
//{
//     int i, flow, fmin, x, y, z, nod;
//
//    f>>N>>M;
//
//    for (i = 1; i <= M; i++)
//    {
//        f>>x>>y>>z;
//        C[x][y] += z;
//        G[x].pb(y);
//        G[y].pb(x);
//    }
//
//    for (flow = 0; BF(); flow += fmin)
//    {
//        fmin = INF;
//        for (nod = N; nod != 1; nod = TT[nod])
//            fmin = min(fmin, C[ TT[nod] ][nod] - F[ TT[nod] ][nod]);
//        for (nod = N; nod != 1; nod = TT[nod])
//        {
//            F[ TT[nod] ][nod] += fmin;
//            F[nod][ TT[nod] ] -= fmin;
//        }
//    }
//
//    g<<flow<<'\n';
//    return 0;
//}