Cod sursa(job #156728)
Utilizator | Data | 12 martie 2008 18:34:15 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.43 kb |
# include <stdio.h>
# define input "ciur.in"
# define output "ciur.out"
# define max 1000001
int n,a[max],i,j,res;
int main()
{
freopen(input, "r", stdin);
freopen(output, "w", stdout);
scanf("%d",&n);
for(i=2;i<=n;i++)
if(!a[i])
{
res++;
for(j=i+i;j<=n;j+=i)
a[j] = 1;
}
printf("%d",res);
return 0;
}