Cod sursa(job #2695932)

Utilizator SirbuSirbu Ioan Sirbu Data 14 ianuarie 2021 21:40:50
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.33 kb
#include <bits/stdc++.h>
#define NMAX 1005
#define inf 9999999

using namespace std;

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



int n,m,val[NMAX][NMAX],cap[NMAX][NMAX],tata[NMAX],drum[NMAX];
bool fost[NMAX];
vector<int>vecini[NMAX];

bool arb() {

 for(int i=1;i<=n;i++)
    fost[i]=0;

 int nr=1; drum[1]=1; fost[1]=1;

 for(int i=1;i<=nr;i++) {

   int nod=drum[i];
   if(nod==n)
    continue;

   for(int j=0;j<vecini[nod].size();j++) {
     int x=vecini[nod][j];
     if(fost[x]||cap[nod][x]==val[nod][x])
        continue;

     fost[x]=1;
     tata[x]=nod;
     drum[++nr]=x;
   }
 }
 return fost[n];

}

int main(){

 fin>>n>>m;
 for(int i=1;i<=m;i++) {
  int x,y,z;
  fin>>x>>y>>z;
  val[x][y]=z;
  vecini[x].push_back(y);
  vecini[y].push_back(x);
 }
 int fluxmax=0,flux=0;

 while(arb()) {

   for(int i=0;i<vecini[n].size();i++) {

     flux=inf;
     int nod=vecini[n][i];

     if(!fost[nod]||cap[nod][n]==val[nod][n])
        continue;

     tata[n]=nod;
     for(int j=n ; j!=1 ; j=tata[j])
        flux=min(flux,val[tata[j]][j]-cap[tata[j]][j]);

     if( flux==0 )
        continue;

     for(int j=n ; j!=1 ; j=tata[j]){
       cap[tata[j]][j]+=flux;
       cap[j][tata[j]]-=flux;
     }
     fluxmax+=flux;
   }
 }
 fout<<fluxmax;
 return 0;
}