Cod sursa(job #409766)

Utilizator andunhillMacarescu Sebastian andunhill Data 3 martie 2010 21:01:35
Problema Ciurul lui Eratosthenes Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include<fstream.h>
using namespace std;
char x[2500000];
int main()
{ ifstream f("ciur.in"); ofstream g("ciur.out");
  int n,nr=0,i,j=2; bool stop=0;  
  f>>n;
  for(i=2;i<=7;i++)
  { stop=0; j=i;
	  for(j+=i;j<=n;j+=i)
	 if(x[j]!=1)
		x[j]=1;
  }
 for(i=2;i<=n;i++)
	if(x[i]==0)
	 nr++;
 g<<nr;
 f.close(); g.close();
 return 0;
}