Cod sursa(job #305424)
Utilizator | Data | 17 aprilie 2009 11:39:55 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include <fstream.h>
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int v[2000001];
long i,k,n,a;
int main() {
fin>>n;
for (i=2;i<=n;++i)
if (v[i]==0)
{
for (k=2*i;k<=n;k+=i)
if (v[k]==0)
v[k]=1;
a++;
}
fout<<a;
return 0;
}