Cod sursa(job #448870)

Utilizator djand3y93Pricop Andrei djand3y93 Data 4 mai 2010 21:36:14
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
# include <fstream.h>
int v[20000000];
int main()
{int n,i,j,nr=0;
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;i++) v[i]=1;
  for(i=2;i*i<=n;i++)
    if(v[i]==1) for(j=2;j*i<=n;j++) v[i*j]=0;

for(int i=2;i<=n;i++)
	if(v[i]==1)nr++; 
g<<nr;
f.close ();
g.close ();
return 0;
}