Cod sursa(job #293195)

Utilizator hurrycaneBogdan Gaza hurrycane Data 1 aprilie 2009 01:04:23
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<fstream>
#include<math.h>

using namespace std;

fstream f,g;

int N;
int T;
int i,j;

int main(){
	int *s=new int[2000100];
	f.open("ciur.in",ios::in);
	g.open("ciur.out",ios::out);

	f>>N;
	for(i=2;i<=N;i++){
		if(s[i]==0){
			++T;
			for(j=2;j<=N/i;j++){
				s[i*j]=1;
			}
		}
	}
	g<<T;
	
	return 0;
}