Cod sursa(job #1355664)

Utilizator catalinagherasim1Catalina Gherasim catalinagherasim1 Data 22 februarie 2015 21:57:47
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.36 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;

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

int n, nr;
bool  p[2000001];

int main()
{
	fin >> n;
	int i, j;
	i = 2;
	do 
	{
		if (p[i] == 0)
		{
			nr++;
			for (j = i * i; j <= n; j += i)
				p[j] = 1;
		}
		i++;
	}
	while ( i <= n);
	fout << nr << '\n';
	return 0;
}