Cod sursa(job #2204933)

Utilizator daniela12Sandu Daniela Teodora daniela12 Data 17 mai 2018 11:48:06
Problema Flux maxim Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.49 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <list>
#include <set>
#include <queue>
using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");

int n, m;
vector<list<int>> graf(1004);
int F[1005][1005], C[1005][1005];
vector<int> t(1004);
int BFS ()
{
    set <int> viz;
    queue <int> p;
    int x=1;
    p.push(x);
    viz.insert(x);
    t[1]=0;
    while(!p.empty() && !viz.count(n))
    {
        for(int i=1;i<=n;i++)
        {
            if(C[x][i] != F[x][i] && !viz.count(i))
                {
                    p.push(i);
                    viz.insert(i);
                    t[i]=x;
                }
        }
        p.pop();
        x=p.front();
    }
    if(!viz.count(n))
        return 0;
    int minim=INT_MAX;
    int i=n;
    while(t[i]!=0)
    {
        if(C[t[i]][i]-F[t[i]][i]<minim)
            minim=C[t[i]][i]-F[t[i]][i];
        i=t[i];
    }
    i=n;
    while(t[i]!=0)
    {
        F[t[i]][i]+=minim;
        F[i][t[i]]-=minim;
        i=t[i];
    }
    return minim;

}
int main()
{
    int i;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        int x, y, c;
        f>>x>>y>>c;
        graf[x].push_back(y);
        graf[y].push_back(x);
        C[x][y]=c;
    }
    f.close();
    ///1 nodul sursa
    ///n nodul destinatie
    int flux=0;
    while(true)
    {
        int ok=BFS();
        if(ok==0)
            break;
        flux+=ok;
    }
    g<<flux;
    g.close();
}