Cod sursa(job #1507350)

Utilizator TibixbAndrei Tiberiu Tibixb Data 21 octombrie 2015 17:02:57
Problema Flux maxim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.81 kb
#include<fstream>
#include<vector>
#include<bitset>
#include<deque>
using namespace std;
vector <int> L[1003];
bitset<1003> u;
deque <int> q;
int T[1003], n, m, i, x, y, z, C[1003][1003], nod, minim, F[1003][1003], flux, ok, vecin;
int bfs()
{
    q.clear();
    u.reset();
    q.push_back(1);
    u[1]=1;
    ok=0;
    while(!q.empty())
    {
        int nod=*q.begin();
        if(nod==n)
        {
            ok=1;
            break;
        }
        for(int i=0; i<L[nod].size(); i++)
        {
            vecin=L[nod][i];
            if(u[vecin]==0 && C[nod][vecin]-F[nod][vecin]>0)
            {
                q.push_back(vecin);
                T[vecin]=nod;
                u[vecin]=1;
            }
        }
        q.pop_front();
    }
    return ok;
}
ifstream in("maxflow.in");
ofstream out("maxflow.out");
int main()
{
    in>>n>>m;
    for(i=1; i<=m; i++)
    {
        in>>x>>y>>z;
        L[x].push_back(y);
        L[y].push_back(x);
        C[x][y]=z;
    }
    while(bfs())
    {
        for(i=0; i<L[n].size(); i++)
        {
            nod=L[n][i];
            if(u[nod]==1)
            {
                minim=C[nod][n]-F[nod][n];
                for(; T[nod]!=0 && minim!=0; nod=T[nod])
                {
                    minim=min(minim, C[T[nod]][nod]-F[T[nod]][nod]);
                }
                if(minim!=0)
                {
                    flux+=minim;
                    nod=L[n][i];
                    F[nod][n]+=minim;
                    F[n][nod]-=minim;
                    for(; T[nod]!=0; nod=T[nod])
                    {
                        F[T[nod]][nod]+=minim;
                        F[nod][T[nod]]-=minim;
                    }
                }
            }
        }
    }
    out<<flux;
    return 0;
}