Cod sursă (job #147302)

#include <cstdio>
#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];
                if (nod == N) continue;
        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;
            }
    }

    return viz[N];
}

int main()
{
    freopen("push-relabel.in", "r", stdin);
    freopen("push-relabel.out", "w", stdout);

    int i, flow, fmin, nod;

    scanf("%d", &N);

    for (int l = 1; l <= N; l++)
      for (int c = 1; c <= N; c++)
    {
        scanf("%d", &C[l][c]);
        G[l].pb(c);
        G[c].pb(l);
    }

    for (flow = 0; BF();)
        for (i = 0; i < G[N].sz; i++)
        {
            nod = G[N][i];
            if (F[nod][N] == C[nod][N] || !viz[nod]) continue;
            TT[N] = nod;

            fmin = INF;
            for (nod = N; nod != 1; nod = TT[nod])
                fmin = min(fmin, C[ TT[nod] ][nod] - F[ TT[nod] ][nod]);
            if (fmin == 0) continue;

            for (nod = N; nod != 1; nod = TT[nod])
            {
                F[ TT[nod] ][nod] += fmin;
                F[nod][ TT[nod] ] -= fmin;
            }

            flow += fmin;
        }

    printf("%d ", flow);
    return 0;
}