Cod sursa(job #839998)

Utilizator alexalbu95Albu Alexandru alexalbu95 Data 22 decembrie 2012 12:48:32
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include<cstdio>

bool a[2000000];

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