Cod sursa(job #588359)

Utilizator lily3Moldovan Liliana lily3 Data 7 mai 2011 19:06:52
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;

unsigned long i,n,a[2000001],nr=0;
int ciur()
{
	int i,j;
	nr=n;
	for(i=2;i*i<=n;i++)
	{
		if(!a[i])
		{
			for(j=i+i;j<=n;j+=i)
				a[j]=1,nr--;
		}
	}
	return nr;
}
int main()
{
	ifstream f("ciur.in");
	ofstream g("ciur.out");
	f>>n;
	g<<ciur();
		return 0;
}