Cod sursa(job #1373182)

Utilizator nicol.bolasNicol Bolas nicol.bolas Data 4 martie 2015 17:12:06
Problema Flux maxim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.51 kb
#include<fstream>
#include<vector>
#include<queue>
#include<bitset>
using namespace std;
ifstream fin("maxflow.in");
ofstream fout("maxflow.out");
vector <int> v[1005];
queue <int> q;
bitset <1005> viz;
int n,m,x,y,c,minim,flux,F[1005][1005],C[1005][1005],T[1005];
int bfs()
{
    int i;
    viz.reset();
    T[1]=0, viz[1]=1;
    q.push(1);
    while (!q.empty())
    {
        x=q.front(); q.pop();
        for (i=0;i<v[x].size();++i)
        {
            y=v[x][i];
            if (!viz[y] && F[x][y]<C[x][y])
            {
                viz[y]=1, T[y]=x;
                q.push(y);
            }
        }
    }
    return viz[n];
}
int main()
{
    int i;
    fin>>n>>m;
    for (i=1;i<=m;++i)
    {
        fin>>x>>y>>c;
        v[x].push_back(y);
        v[y].push_back(x);
        C[x][y]=c;
    }
    while (bfs())
    {
        for (i=0;i<v[n].size();++i)
            if (F[v[n][i]][n]<C[v[n][i]][n] && viz[v[n][i]])
            {
                x=v[n][i];
                minim=C[x][n]-F[x][n];
                while (T[x])
                {
                    minim=min(minim,C[T[x]][x]-F[T[x]][x]);
                    x=T[x];
                }
                flux+=minim;
                x=v[n][i];
                F[x][n]+=minim, F[n][x]-=minim;
                while (T[x])
                {
                    F[T[x]][x]+=minim, F[x][T[x]]-=minim;
                    x=T[x];
                }
            }
    }
    fout<<flux<<"\n";
    return 0;
}