Cod sursa(job #1474793)

Utilizator tudorgalatanRoman Tudor tudorgalatan Data 22 august 2015 22:55:39
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.27 kb
Raporteaza aceasta sursa 
#include <fstream>

using namespace std;

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

bool c[2000001];
int n, i, j, nr;

int main ()
{
	f >> n;
	for (i=2; i<=n; i++)
	{
		if (c[i] == 0)
		{
			nr++;
			for (j=i*2; j<=n; j=j+i)
				c[j] = 1;
		}
	}
	g << nr;
	return 0;
}