Cod sursa(job #353093)

Utilizator bgmunteanuMunteanu Bogdan bgmunteanu Data 4 octombrie 2009 08:47:51
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
#include <fstream>
using namespace std;
int main()
{
	char v[2000000];
	int i,n,j,nr=0;
	ifstream fin("ciur.in");
	ofstream fout("ciur.out");
	fin>>n;
	for (i=2;i<=n;i++) v[i]=1;
	for (i=2;i<=n;i++)
		{
			if (v[i]==1) 
			{   
				nr++;
				for (j=i+i;j<=n;j=j+i) v[j]=0;
			}
		}
	fout<<nr;
	fout.close();
	fin.close();
	return 0;
}