Cod sursa(job #458697)

Utilizator attila3453Geiszt Attila attila3453 Data 25 mai 2010 21:00:08
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.28 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
ifstream fi("ciur.in");
ofstream fo("ciur.out");
int i, j, n, s=0, prim[2000001];
int main(){
  fi>>n;
  for(i=2;i<=n;i++)
	if(prim[i]==0)
	  for(j=i*2;j<=n;j+=i)
		prim[j]=1; 
  for(i=2;i<=n;i++)
	if(prim[i]==0)
	  s++;
  fo<<s;
}