Cod sursa(job #1206347)

Utilizator pentrusandaPentru Sanda pentrusanda Data 9 iulie 2014 18:11:41
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.82 kb
#include <fstream>
#include <iostream>
#include <cstring>

using namespace std;

int n,m,c[1005][1005],f[1005][1005],x,y,z,mda[1005][1005],lista[1005],trecut[1005],prec[1005],sol;

int main()
{
    ifstream in ("maxflow.in");
    ofstream out ("maxflow.out");

    in>>n>>m;

    for (int i=1;i<=m;++i)
    {
        in>>x>>y>>z;
        c[x][y]+=z;
        mda[x][y]=1;
        mda[y][x]=1;
    }

    int advr=1;

    while (advr==1)
    {
        memset(trecut,0,sizeof(trecut));
        lista[0]=1; lista[1]=1; trecut[1]=1;
        for (int i=1;i<=lista[0];++i)
        {
            //cout<<lista[i]<<" ";
            int v=lista[i];
            if (v!=n)
            for (int j=1;j<=n;++j)
            {
                if (mda[v][j]==1 && trecut[j]==0 && c[v][j]>f[v][j])
                {
                    ++lista[0]; lista[lista[0]]=j; trecut[j]=1; prec[j]=v;
                }
            }
        } //cout<<"\n";



        if (trecut[n]==1)
        {
            for (int i=1;i<n;++i)
            {
                if (mda[i][n]==1 && trecut[i]==1 && c[i][n]>f[i][n])
                {
                    prec[n]=i;
                    int minim=c[i][n]-f[i][n],v=n;

                    while (v!=1)
                    {
                        if (minim>c[prec[v]][v]-f[prec[v]][v]) minim=c[prec[v]][v]-f[prec[v]][v];
                        v=prec[v];
                    }

                    v=n;
                    while (v!=1)
                    {
                        f[prec[v]][v]+=minim;
                        f[v][prec[v]]-=minim;
                        v=prec[v];
                    }

                    sol+=minim;
                }
            }
        } else advr=0;
    }

    out<<sol;

    in.close();
    out.close();
    return 0;
}