Cod sursa(job #1476182)

Utilizator floreaadrianFlorea Adrian Paul floreaadrian Data 24 august 2015 16:28:27
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<fstream>

using namespace std;

ifstream fin("ciur.in");
ofstream fout("ciur.out");

char ciur[2000001];

int main()
{
	int n,c=0,i,d;
	fin>>n;
	for(d=2;d*d<=n;d++)
	  if(ciur[d]==0)
		for(i=d*d;i<=n;i=i+d)
		  ciur[i]=1;
	for(i=2;i<=n;i++)
	if(!ciur[i])
	c++;
	fout<<c;
	return 0;
}