Cod sursa(job #550139)
Utilizator | Data | 9 martie 2011 11:48:51 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include<fstream.h>
int main()
{
ifstream fin("numar.in");
ofstream fout("prim.out");
long long n,i,d,s=0,p,x;
fin>>n;
for(i=2;i<=n;i++)
{
x=sqrt(i);p=1;
for(d=2;d<=x&&p==1;d++)
if(i%d==0) p=0;
if(p==1) {s++;}
}
fout<<s;
return 0;
}