Cod sursa(job #444933)
Utilizator | Data | 22 aprilie 2010 09:39:34 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int n, i, no;
char p[2000000];
void sterge(int k)
{ for(int j=k; j<=n; j+=k)
p[j]='x';
}
int main()
{
fin>>n;
for(i=2;i<=n;i++) if( p[i] == 'x' ) ++no, sterge(i);
fout<<no;
return 0;
}