Cod sursa(job #2124424)

Utilizator alexandruilieAlex Ilie alexandruilie Data 7 februarie 2018 10:59:04
Problema Flux maxim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.4 kb
#include <fstream>
#define nmax 1001
#include <vector>
#include <queue>
#include <iomanip>
#include <string.h>
using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");
vector <int> v[nmax];
int t[nmax],C[nmax][nmax],F[nmax][nmax],a,b,c,FC,FL,n,m;
int BF()
{
    queue <int> q;
    memset(t,0,sizeof(t));
    t[1]=-1;
    q.push(1);
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        for(int i=0;i<v[nod].size();i++)
        {
            int vec=v[nod][i];
            if(t[vec]||C[nod][vec]==F[nod][vec]) continue;
            t[vec]=nod;
            q.push(vec);
            if(vec==n) return 1;
        }
    }
    return 0;
}
void dinic()
{
    int j;
    while(BF())
        for(int i=1;i<=n;i++)
        {if(!t[i]||C[i][n]==F[i][n]) continue;
            FC=C[i][n]-F[i][n];
            for(j=i;j>1;j=t[j])
                FC=min(FC,C[t[j]][j]-F[t[j]][j]);
            if(!FC) continue;
                F[i][n]+=FC;
                F[n][i]-=FC;
                for(j=i;j>1;j=t[j])
                {
                    F[t[j]][j]+=FC;
                    F[j][t[j]]-=FC;
                }
        FL+=FC;}

}
int main()
{
    int i;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>a>>b>>c;
        v[a].push_back(b);
        v[b].push_back(a);
        C[a][b]=c;
    }
    dinic();
    g<<FL;
    return 0;
}