Cod sursa(job #296043)

Utilizator lucianvnDragomir Lucian lucianvn Data 4 aprilie 2009 01:42:13
Problema Ciurul lui Eratosthenes Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.36 kb
#include<fstream.h>
ifstream intrare ("ciur.in");
ofstream iesire ("ciur.out");
long long unsigned v[100000];
int main()
{
	long long unsigned n,j;
	unsigned nr,i;
	intrare>>n;
	for(i=2;i<=7;i++)
	{
		if(v[i]==0)
		{
			for(j=i+i;j<=n;j+=i)
			{
				v[j]=1;
			}
		}
	}
	nr=0;
	for(i=2;i<=n;i++)
	{
		if(v[i]==0) nr++;
	}
	iesire<<nr;
	return 0;
}