Cod sursa(job #786485)
Utilizator | Data | 11 septembrie 2012 15:26:54 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
long n,v[2000001],i,j,nr;
int main()
{
f>>n;
for (i=2;i<=n;i++)
if (v[i]==0)
for (j=i+i;j<=n;j=j+i)
v[j]=1;
for (i=2;i<=n;i++)
if (v[i]==0)
nr++;
g<<nr;
f.close();
g.close();
return 0;
}