Cod sursa(job #894880)

Utilizator mmanMihai Manolescu mman Data 27 februarie 2013 00:42:30
Problema Ciurul lui Eratosthenes Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 0.36 kb
Raporteaza aceasta sursa 
#include<fstream>
#define dmax 2000002
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");

int main()
{
	int n;
	
	in>>n;
	in.close();
	
	bool x[dmax];

	
	int nr = 0;

	for(int i=2; i <= n; i++)
		if(x[i] == 0)
		{
			nr++;

			for(int j=i; j <= n; j+=i)
				x[j] = 1;
		}

	out<<nr;
	
	out.close();
	return 0;
}