Cod sursa(job #688371)

Utilizator stefaniaaStefania Aungurencei stefaniaa Data 23 februarie 2012 15:18:59
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.29 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
long n,i,k,j;
char v[2000003];
int main()
{
	f>>n;
	k=n-1;
	for (i=2;i<=n;i++)
		if (!v[i])
			for (j=2*i;j<=n;j+=i)
			{
				if (!v[j]) k--;
				v[j]='*';
			}
	g<<k<<'\n';
	return 0;
}