Cod sursa(job #1158762)

Utilizator nickulNic Kul nickul Data 29 martie 2014 02:22:27
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include<fstream>
#include<set>

using namespace std;

ifstream in("ciur.in");
ofstream out("ciur.out");

int main()
{
	set<int> sol;
	int n,i;
	set<int>::iterator it;
	in>>n;
	for(i=3;i<=n;i+=2)
		sol.insert(i);
	for(it=sol.begin();it!=sol.end();it++)
		for(i=3**it;i<=n;i+=2**it)
			sol.erase(i);
	out<<sol.size()+1;
}