Cod sursa(job #481042)

Utilizator marta_diannaFII Filimon Marta Diana marta_dianna Data 30 august 2010 14:06:24
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<fstream.h>
#define NMAX 2000002

bool a[NMAX];
int i, j, n, nr;

int main()
{
	ifstream f("ciur.in");
	ofstream g("ciur.out");
	
	f>>n;
	for (i=2; i<=n; ++i)
		if (!a[i])
		{
			++nr;
			for (j=i+i; j<=n; j+=i)
				a[j]=true;
		}
	
	g<<nr<<"\n";
	f.close();
	g.close();
	return 0;
}