Cod sursa(job #188982)

Utilizator jupanubv92Popescu Marius jupanubv92 Data 11 mai 2008 12:25:21
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include<stdio.h>

long n,nr;
unsigned char a[2000001];

void solve()
{
 for(long i=2;i<=n;i++)
  if(a[i]==0)
  {
   nr++;
   for(long j=1;i*j<=n;j++)
      a[j*i]=1;
   }

}

int main()
{
 freopen("ciur.in","r",stdin);
 freopen("ciur.out","w",stdout);
 scanf("%ld",&n);
 solve();
 printf("%ld",nr);
 return 0;
 }