Cod sursa(job #861905)

Utilizator ion_calimanUAIC Ion Caliman ion_caliman Data 21 ianuarie 2013 23:40:11
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 2.55 kb
#include <stdio.h>
#include <vector>
#include <queue>

using namespace std;

#define NMAX 1024
#define INF 0x3f3f3f3f
#define pop() front(); Q.pop()

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 fmin[NMAX];
int flow;

void BF()
{
    int i, j, nod, V, s=1, t=N;

    queue<int> Q;

    for (i=0; i<=N; i++) viz[i]=0;
    Q.push(s);
    viz[s] = 1;
    fmin[s] = INF;

    while (!Q.empty()) //cd != NULL
    {
        nod = Q.pop();
        //printf("pop -%d\n",nod);

        for (j = 0; j < G[nod].size(); j++)
            {
                V = G[nod][j];

                if (C[nod][V] == F[nod][V] || viz[V]) continue;
                viz[V] = 1;

                Q.push(V);
                TT[V] = nod;

                if (C[nod][V])
                    fmin[V] = min(fmin[nod], C[nod][V] - F[nod][V]);
                else
                    fmin[V] = min(fmin[nod], F[V][nod]);

                if (V == t) {
                    for (nod = t; nod != s; nod = TT[nod])
                    {
                        F[ TT[nod] ][nod] += fmin[N];
                        F[nod][ TT[nod] ] -= fmin[N];
                        //viz[nod] = 0;
                    }
                    flow += fmin[N];
                    BF();
                    return;
                }
            }
    }
}

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

    int i, x, y, z;

    scanf("%d %d ", &N, &M);

    for (i = 1; i <= M; i++)
    {
        scanf("%d %d %d ", &x, &y, &z);
        C[x][y] += z;
        G[x].push_back(y);
        G[y].push_back(x);
    }


    BF();

    printf("%d ", flow);
    return 0;
}
/*
#include <stdio.h>
#include <vector>
#include <stack>

using namespace std;

#define pop() top(); S.pop()
#define v in

vector<int> A[1024];
int COST[1024][1024];
int FLUX[1024][1024];
int N, M;
int s, t, v;
stack <int> S;
int TT[1024];
int len;


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

    scanf("%d %d", &N, &M);
    int i, x, y, c;
    for (i=0; i<M; i++) {
        scanf("%d %d %d", &x, &y, &c);
        COST[x][y] = c;
        A[x].push_back(y);
        A[y].push_back(x);
    }

    s = 1; t = N;

    S.push(s);
    TT[s] = s;
    while (!S.empty()) {
        x = S.pop();
        for(i=0; i<A[x].size(); i++) {
            v = A[x][i];

            S.push(v)
        }
    }
}
*/