Cod sursa(job #445377)
Utilizator | Data | 23 aprilie 2010 17:32:03 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include <stdio.h>
int a[2000010],i,j,N,nr;
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%i",&N);
a[1]=1;
for(j=2;j<=N;j++)
{
if(!a[j])
{
for(i=2;i<=N;i++)
if(!(i%j) && i!=j) a[i]=1;
}
}
for(i=1;i<=N;i++) if(!a[i]) nr++;
printf("%i",nr);
return 0;
}