Cod sursa(job #1048064)

Utilizator paunmatei7FMI Paun Matei paunmatei7 Data 5 decembrie 2013 11:11:43
Problema Flux maxim Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.76 kb
#include<stdio.h>
#include<vector>
#include<string.h>

#define NMAX 10007

using namespace std;

vector<int> v[NMAX];
int q[NMAX], dad[NMAX], Cap[NMAX][NMAX];
int n, m;

inline int min(int a, int b){
    if(a > b)
        return b;
    return a;
}

void bfs(int st, int dr){
    int start = 0, avans = 0;
    q[avans++] = st;
    dad[st] = -2;
    while(avans > start && dad[dr] == -1){
        int Nod = q[start++];
        for(int i = 0; i < v[Nod].size(); ++ i)
            if(dad[v[Nod][i]] == -1 && Cap[Nod][v[Nod][i]]){
                q[avans++] = v[Nod][i];
                dad[v[Nod][i]] = Nod;
            }
    }
}

inline int dinic(int n, int st, int dr){
    int MaxFlow = 0;
    while(1){
        memset(dad, -1, sizeof(dad));
        dad[1] = -2;
        bfs(st, dr);
        if(dad[dr] == -1)
            break;
        for(int i = 1; i <= n; ++i){
            if(Cap[i][dr] && dad[i] != -1){
                int Min = Cap[i][dr];
                for (int v = i, u = dad[v]; u >= 0; v = u, u = dad[v])
                    Min = min(Min, Cap[u][v]);
                if(! Min)
                    continue;
                for (int v = i, u = dad[v]; u >= 0; v = u, u = dad[v]){
                    Cap[u][v] -= Min;
                    Cap[v][u] += Min;
                }
                MaxFlow += Min;

            }
        }
    }
    return MaxFlow;
}

int main(){
    freopen("maxflow.in", "r", stdin);
    freopen("maxflow.out", "w", stdout);
    scanf("%d %d", &n, &m);
    for(int i = 1; i <= m; ++i){
        int a = 0, b = 0, c = 0;
        scanf("%d %d %d", &a, &b, &c);
        v[a].push_back(b);
        v[b].push_back(a);
        Cap[a][b] += c;
    }
    printf("%d", dinic(n, 1, n));
    return 0;
}