Cod sursa(job #156143)

Utilizator pikuAnca Miihai piku Data 12 martie 2008 13:07:38
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.29 kb
Raporteaza aceasta sursa 
#include<cstdio>
#define nmax 2000010

int n, v[nmax];

int main()
{
 int i, j, count=0;
 freopen("ciur.in", "r", stdin);
 freopen("ciur.out", "w", stdout);
 scanf("%d", &n);
 for(i=2; i<=n; i++)
  if(!v[i])
   {
		for(j=2*i; j<=n; j+=i)
			v[j] = 1;
		count++;
   }
 printf("%d", count);
 return 0;
}