Cod sursa(job #2752955)

Utilizator madalina.andronAndronache Madalina madalina.andron Data 20 mai 2021 15:55:20
Problema Flux maxim Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.32 kb
#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

ifstream fin("maxflow.in");
ofstream fout("maxflow.out");

int N,M, x,y,z,flux;
int C[1005][1005], F[1005][1005], T[1005];

void citire()
{
    fin>>N>>M;
    for(int i=1;i<=M;i++)
    {
        fin>>x>>y>>z;
        C[x][y]=z;
    }
}
int BFS(int s,int d)
{
    int p,u,nod,Q[1005];
    memset(T, 0,sizeof(T));
    p=u=1;
    Q[p]=s;
    T[s]=-1;
    while(p<=u)
    {
        nod=Q[p];
        for(int i=1;i<=N;i++)
            if(T[i]==0 && C[nod][i]>F[nod][i])
            {
                Q[++u]=i;
                T[i]=nod;
                if(i==d) return i;
            }
        p++;
    }
    return 0;
}
void flux_maxim()
{
    int r,i,j;
    int s=1, d=N;
    for(flux=0; BFS(s,d);)
    {
      for(i=1;i<=N;i++)
      {
          if(T[i]==0||C[i][d]<=F[i][d]) continue;
          r=C[i][d]-F[i][d];
          for(j=i; j!=s && j; j=T[j])
              r=min(r, C[T[j]][j]-F[T[j]][j]);
          if(r==0) continue;
          F[i][d]+=r;
          F[d][i]-=r;
          for(j=i; j!=s; j=T[j])
          {
              F[T[j]][j]+=r;
              F[j][T[j]]-=r;
          }
          flux+=r;
      }
    }
    fout<<flux;
}

int main()
{
    citire();
    flux_maxim();
    return 0;
}