Cod sursa(job #438037)
Utilizator | Data | 10 aprilie 2010 14:01:04 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include<stdio.h>
int n,nr=0;
char prim[20005];
int main()
{
int i,j;
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
for(i=2;i<=n;i++)
prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i]==1)
{
nr++;
for(j=i+i;j<=n;j+=i)
prim[j]=0;
}
printf("%d\n",nr);
return 0;
}