Cod sursa(job #232942)
Utilizator | FMI Carol Plangu carlone | Data | 16 decembrie 2008 15:14:48 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include"stdio.h"
long n,q=1,pr[1000000];
int prim(long r)
{for(long g=0;pr[g]*pr[g]<=r;g++)if(r%pr[g]==0)return 0;
pr[q]=r;return 1;}
void genprime(long n)
{for(long g=2;pr[q-1]<=n;g++)
{if(prim(g))q++;}q-=2;}
int main()
{pr[0]=2;freopen("ciur.in","r",stdin);freopen("ciur.out","w",stdout);scanf("%ld",&n);genprime(n);printf("%d",q);
return 0;}