Cod sursa(job #1247822)

Utilizator ArkinyStoica Alex Arkiny Data 23 octombrie 2014 23:45:42
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
#include<fstream>
using namespace std;


long v[2000000];

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

int main()
{ 
	long N,nr=0;;
	in>>N;

	for(int i=2;i<=N;i++)
	{
		if(!v[i])
			nr++;
		for(int j=2;j<=N/i;j++)
			v[i*j]=1;
	}
	out<<nr;
	in.close();
	out.close();
	return 0;
}