Cod sursa(job #788319)

Utilizator Ionut228Ionut Calofir Ionut228 Data 14 septembrie 2012 14:47:35
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
#include<fstream>
using namespace std;

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

int v[2000000],n,i,j,nr;

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