Cod sursa(job #1799631)

Utilizator Martin00Ionescu Martin Martin00 Data 6 noiembrie 2016 16:17:23
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
#include<iostream>
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int n,i,j,v[2000001],s;
int main (){
	cin>>n;
	i=2;
	s=n-1;
	for(i=2;i*i<=n;i++){
		if(v[i]==0)
			for(j=i*i;j<=n;j=j+i){
				v[j]=1;
				s=s-1;
			}
	}
	cout<<s;
	
	return 0;
}