Sieve of Eratosthenes

//https://practice.geeksforgeeks.org/problems/sieve-of-eratosthenes/0
#include <bits/stdc++.h>
using namespace std;
typedef long long ll ; 
ll const N = 1e4 + 1 ; 
ll arr [  N ] ; 
void cal ( )
{
    for ( ll i = 1 ; i <= N  ; i ++ )
            arr [ i ] =  1 ; 
            
    for ( int i = 2 ; i * i <= N  ; i ++ )
    {
            if ( arr [ i ] )
            {
                // cout << i << " " ; 
                for ( ll j =  i * i  ; j <= N  ; j += i  )
                {
                    arr [ j ] =  0 ; 
                }
            }
    }
}
int main() {
    
   //ios_base::sync_with_stdc; cin.tie(0);cout.tie (0) ; 
    ll T ; 
    cin >> T ;
   // cout << T  << " ***" << endl ; 
    cal () ; 
    //cout << T << endl ; 
    while ( T-- )
    {
        ll n ; 
        cin >> n ;
        for ( int i = 2 ; i  <= n ; i ++ )
        {
            if ( arr [ i ] )
            {
                cout << i  << " " ; 
                
            }
        }
        cout << endl ; 
    }
	//code
	return 0;
}