Cod sursa(job #2189142)

Utilizator Valy11Achimescu Valentin Valy11 Data 27 martie 2018 19:05:31
Problema Flux maxim Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.66 kb
#include <iostream>
#include <fstream>
#include <cmath>
#include <cstring>
using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");
int i,flux,j,x,y,c,n,m,s,d,q[1001],viz[1001],F[1001][1001],C[1001][1001],G[1001][1001];
void read()
{
    f>>n>>m;
    s=1;
    d=n;
    for(i=1;i<=m;++i)
    {
        f>>x>>y>>c;
        C[x][y]=c;
        ++G[x][0];
        G[x][G[x][0]]=y;
        ++G[y][0];
        G[y][G[y][0]]=x;
    }
}
int bfs()
{
    int i,u,p,x;
    p=1;
    u=1;
    q[p]=s;
    viz[s]=1;
    while(p<=u && !viz[d])
    {
        x=q[p];
        ++p;
        if(x==n)
            continue;
        for(i=1;i<=G[x][0];++i)
        if(!viz[G[x][i]])
            if(F[x][G[x][i]]<C[x][G[x][i]])
            {
                q[++u]=G[x][i];
                viz[G[x][i]]=x;
            }

    }
    if(viz[d])
        return 0;
    return 1;
}
void ek()
{
    int i,a,b,lg,v;
    int L[1001];
    do
    {

        memset(viz, 0, sizeof(viz));
        if(bfs())
            return;

        int nod=n;
        a=110001;
        while(nod!=1)
        for(i=1;i<=G[n][0];++i)
        {
            nod=G[n][i];
            if(viz[nod]==0 || C[nod][n]==F[nod][n])
            continue;
            a=min(a,C[viz[nod]][nod]-F[viz[nod]][nod]);
            nod=viz[nod];
        }
        v=a;
        nod=n;
        while(nod!=1)
        {
                F[viz[nod]][nod]+=v;
                F[nod][viz[nod]]-=v;
                nod=viz[nod];
        }
        flux=flux+v;
    }while(1);
}
void afis()
{
    g<<flux<<'\n';
}
int main()
{
    read();
    ek();
    afis();
    return 0;
}