Cod sursa(job #1536824)

Utilizator ZimmyZimmermann Erich Zimmy Data 26 noiembrie 2015 18:24:29
Problema Flux maxim Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
#define N 1024
using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");
int n,m,x,y,z,C[N][N],F[N][N],flow,bf(),T[N],i,j,k,ok=1;
vector<int> v[N];
queue<int> Q;
void upd();
int main()
{
    f>>n>>m;
    for(;m;m--)
    {
        f>>x>>y>>z;
        v[x].push_back(y);
        C[x][y]=z;
    }
    while(ok)
    {
        for(i=1;i<=n;i++)
            T[i]=0;
        T[1]=1;
        while(Q.size())Q.pop();
        Q.push(1);
        while(Q.size()&&!T[n])
        {
            j=Q.front();
            Q.pop();
            for(auto it:v[j])
                if(!T[it]&&C[j][it]>F[j][it])
                {
                    T[it]=j;
                    Q.push(it);
                }

        }
        if(!T[n])break;
        for(k=1;k<n;k++)
            if(T[k]&&C[k][n]-F[k][n]>0)
            {
                int flux=C[k][n]-F[k][n];
                for(i=k,j=T[k];i!=j;i=T[i],j=T[j])
                    flux=min(flux,C[j][i]-F[j][i]);
                if(!flux)continue;
                F[k][n]+=flux;
                for(i=k,j=T[k];i!=j;i=T[i],j=T[j])
                    F[j][i]+=flux;
                flow+=flux;
            }
    }
    g<<flow;
    return 0;
}