Cod sursa(job #526817)

Utilizator tudorsTudor Siminic tudors Data 29 ianuarie 2011 16:09:57
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
int n,rez,j,i;
int A[2000001];

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

int main()
{
	f>>n;
	rez=0;
	for (i=2;i<=n;i++)
		if (!A[i])
		{
			rez++;
			for (j=i+i;j<=n;j+=i)
				A[j]=1;
		}
	cout<<rez;
	return 0;
}