Cod sursa(job #158394)

Utilizator sticksuTihu Mircea sticksu Data 13 martie 2008 17:00:52
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include<fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
long prim(long x)
{ long i,c=1;
  for(i=2;i*i<=x;i++)
     if(x%i==0) c=0;
  if(c) return 1;
  else return 0;
}

int main()
{long n,contor=0;
 long i;
 f>>n;
 for(i=2;i<=n;i++)
    if(prim(i)) contor++;
 g<<contor;
 f.close();
 g.close();
 return 0;
}