Cod sursa(job #662631)

Utilizator zeeboBuzatu Vlad zeebo Data 16 ianuarie 2012 21:09:16
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
bool ok[2000001];
int i,j,nr,n;
int main ()
{
f>>n;
for (i=2;i<=n;i++)
ok[i]=true;
for (i=2;i<=n;i++)
if (ok[i])
for (j=i+i;j<=n;j+=i) ok[j]=false;
for (i=2;i<=n;i++) if (ok[i]) nr++;
g<<nr<<'\n';
return 0;
}