Cod sursa(job #2466379)

Utilizator NMadrianNechiti Mihai Adrian NMadrian Data 1 octombrie 2019 23:11:34
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std ;
ifstream in ("ciur.in");
ofstream out ("ciur.out");
int c,n;
short E[2000005] ;
int main(){
int i , j ;
E[0]=E[1]=1;
in >> n;
for(i=2;i*i<=n;i++)
{
    if(E[i]==0)
    for(j=2;j*i<=n;j++)
        E[i*j]=1;

}
for(i=1;i<=n;i++)
    if(E[i]==0)
    c++;
out<<c;
return 0 ;
}