Cod sursa(job #264216)

Utilizator 630r63Ilinca George Mihai 630r63 Data 21 februarie 2009 19:29:09
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.26 kb
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int main()
{
	long n,i,j;
	char v[2000000]={0};
	int a=0;
	f>>n;
	for(i=2;i<=n;i++) if(v[i]==0){ ++a; for(j=i*i;j<=n;j+=i) v[j]=1;}
	g<<a;
f.close();
g.close();
return 0;}