Cod sursa(job #273709)
Utilizator | Data | 8 martie 2009 22:10:16 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include <stdio.h>
long i,j,k,n,prim[1000];
int main()
{freopen("ciur.in","r",stdin);freopen("ciur.out","w",stdout);
scanf("%ld",&n);
k=1;
for(i=3;i<=n;i+=2)
{if(!prim[i])
{k++;{for(j=i*i;j<=n;j+=i)prim[j]=1;}}
}
printf("%ld",k);fclose(stdin);fclose(stdout);
return 0;
}