Cod sursa(job #446720)

Utilizator lupsanraresLupsan Rares Simion lupsanrares Data 26 aprilie 2010 13:58:06
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
int v[2000000];
int main ()
{
	ifstream fin("ciur.in");
	ofstream fout("ciur.out");
	int i,j,n,nr=0;
	fin>>n;
	for(i=2;i*i<=n;i++)
		for(j=2;j*i<=n;j++)
			v[i*j]=1;
	for(i=2;i<=n;i++)
		if(v[i]==0)
			nr++;
	fout<<nr;
	fin.close();
	fout.close();
	return 0;
}