Cod sursa(job #1048483)

Utilizator paunmatei7FMI Paun Matei paunmatei7 Data 5 decembrie 2013 22:01:59
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.72 kb
#include<stdio.h>
#include<vector>
#include<algorithm>
#include<queue>
#include<string.h>

#define x first
#define y second
#define NMAX 1007
#define INF 100000000

using namespace std;

int Cap[NMAX][NMAX], dad[NMAX], q[NMAX];
int n, Maxflow, m;

vector<int> v[NMAX];

inline int 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]] > 0){
                q[avans++] = v[Nod][i];
                dad[v[Nod][i]] = Nod;
                if(v[Nod][i] == n)
                    return 1;
            }
    }
    return 0;
}


inline int father(int Nod, int Min){
    if(Nod == 1)
        return Min;
    int Dad = dad[Nod];
    Min = min(Min, Cap[Dad][Nod]);
    return father(dad[Nod], Min);
}

void father2(int Nod, int Min){
    if(Nod == 1)
        return;
    int Dad = dad[Nod];
    Cap[Nod][Dad] += Min;
    Cap[Dad][Nod] -= Min;
    father2(dad[Nod], Min);
}

inline int Capmax(){
    memset(dad, -1, sizeof(dad));
    while(bfs(1, n)){
        int Min = INF;
        Min = father(n, Min);
        Maxflow += Min;
        father2(n, Min);
        memset(dad, -1, sizeof(dad));
    }
    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", Capmax());
    return 0;
}