Cod sursa(job #551465)

Utilizator GaborGabrielFMI - GabrielG GaborGabriel Data 10 martie 2011 20:08:32
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include <fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,v[100005],a=0,i,j;

int main()
{
	f>>n;
	for(i=1;i<=n;i++)
		v[i]=5;
	for(i=2;i<=n;i++)
	{
		if(v[i]==5)
			for(j=2*i;j<=n;j+=i)
				v[j]=1;
	}
	
	for(i=1;i<=n;i++)
		if(v[i]==5)
			a++;
	g<<a<<'\n';
	f.close();
	g.close();
	return 0;
}