Cod sursa(job #276089)

Utilizator LuffyBanu Lavinia Luffy Data 10 martie 2009 20:43:02
Problema Ciurul lui Eratosthenes Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
Raporteaza aceasta sursa 
#include<fstream.h>
#include<math.h>
int main()
{int a[10000],n,i,j,nr=0;

ifstream f("ciur.in");
ofstream g("ciur.out");

 f>>n;
  for(i=2;i<=n;i++)
   a[i]=1;

  for(i=2;i<=sqrt(n);i++)
   if(a[i]==1)
    for(j=2;j*i<=n;j++)
     a[i*j]=0;

  for(i=2;i<=n;i++)
   if(a[i]==1) nr++;

  g<<nr<<'\n';
f.close();
g.close();
return 0;
}