Cod sursa(job #631739)
Utilizator | Stefan Lache StefanLache | Data | 9 noiembrie 2011 18:44:03 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include<stdio.h>
#include<assert.h>
int n,prim[1000000];
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
int i,j,nr=0;
scanf("%d",&n);
for(i=2;i<=n;i++)
prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i])
{
nr++;
for(j=i+i;j<=n;j+=i)
prim[j]=0;
}
printf("%d ",nr);
return 0;
}