Cod sursa(job #160458)

Utilizator nighthawkghenea alexandru madalin nighthawk Data 15 martie 2008 21:40:17
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include<fstream.h>
#include<math.h>
char a[2000002];
int main()
{ifstream f("ciur.in");
 ofstream g("ciur.out");
 long i,s,n;
 f>>n;
 for(i=2;i<=n;i=i+2)
	a[i]=1;
 s=1;
 for(j=3;j<=sqrt(n);j++)
	{for(i=j;i<=n;i=i+j)
		a[i]=1;
	s++;}
 for(i=sqrt(n);i<=n;i++)
	if(!a[i])
		s++;
 g<<s;
 g.close();
 return 0;
 }