Cod sursa(job #2421990)

Utilizator NineshadowCarapcea Antonio Nineshadow Data 16 mai 2019 21:21:52
Problema Flux maxim Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.43 kb
#include <bits/stdc++.h>
#define MAXN 1005
#define MAXM 5005
#define INF 0x3f3f3f3f
using namespace std;
int n, m, C[MAXN][MAXN], parent[MAXN];

int bfs()
{
    int viz[MAXN];
    memset(viz, 0, (n + 1) * sizeof(int));
    memset(parent, 0, (n + 1) * sizeof(int));
    queue<int> q;
    viz[1] = 1;
    q.push(1);
    
    while(!q.empty()) {
        int nod = q.front();
        q.pop();
        if(nod == n)
            continue;
        for(int i = 1; i <= n; ++i) {
            if(!viz[i] && C[nod][i] > 0) {
                viz[i] = 1;
                parent[i] = nod;
                q.push(i);
            }
        }
    }
    
    return viz[n];
}
int main()
{
    ifstream in("maxflow.in");
    ofstream out("maxflow.out");
    in >> n >> m;
    while(m--) {
        int x, y, z;
        in >> x >> y >> z;
        C[x][y] = z;
    }
    int tflow = 0;
    
    while(bfs()) {
        for(int j = 1; j < n; ++j) {
            if(C[j][n] > 0) {
                parent[n] = j;
                int flow = INF;
                for(int i = n; i != 1; i = parent[i]) {
                    if(C[parent[i]][i] < flow) {
                        flow = C[parent[i]][i];
                    }
                }
                tflow += flow;
                for(int i = n; i != 1; i = parent[i]) {
                    C[parent[i]][i] -= flow;
                    C[i][parent[i]] += flow;
                }
            }
        }
    }
    out << tflow << "\n";
}