Cod sursa(job #439416)
Utilizator | Data | 11 aprilie 2010 16:04:41 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include<stdio.h>
int n,v[2000002],nr;
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
int i,j;
for(i=2;i<=n/2;i++)
if(v[i]==0)
{
for(j=i;j<=n;j=j+i)
v[j]++;
nr++;
}
for(i=n/2+1;i<=n;i++)
if(v[i]==0)
nr++;
printf("%d",nr);
}