Cod sursa(job #279602)
Utilizator | Data | 12 martie 2009 21:30:04 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include<fstream>
#include<math.h>
using namespace std;
ifstream in ("ciur.in");
int main()
{
int n, nr=0;
bool prim;
in>>n;
in.close();
for (int i=2; i<=n;i++)
{ prim=true;
for (int x=2;x<=sqrt(i);x++)
if (i%x==0) {prim=false; break; }
if (prim) nr++;
}
ofstream out ("ciur.out");
out<<nr;
out.close();
return 0;
}