Cod sursa(job #821324)

Utilizator RobertSSamoilescu Robert RobertS Data 22 noiembrie 2012 09:24:09
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
#include<iostream>
#include<fstream>
using namespace std;
#define MAX_N 2000000

long n, contor;
int v[MAX_N];

int main(){
	
	ifstream fin ("ciur.in");
	ofstream fout ("ciur.out");
	
	fin >> n;
	
	for(int i=2; i<=n; i++){
		if(!v[i]){
			contor ++;
			for(int j=i; j<=n; j+= i)
				v[j] = 1;
		}
	}
	
	
	fout << contor ;
	return 0;
}