Cod sursa(job #963324)
Utilizator | Data | 17 iunie 2013 10:14:08 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include<cstdio>
#include<algorithm>
using namespace std;
int v[2000002],i,j,x,n;
int main ()
{
freopen ("ciur.in","r",stdin);
freopen ("ciur.out","w",stdout);
scanf ("%d",&n);
v[1]=1;
for(i=3;i<=n;i+=2)
if(v[i]==0)
{
++x;
for(j=i;j<=n/i;++j) v[j]=1;
}
printf ("%d",x);
return 0;
}