Program to find X-numbers in an array - php

Question

in an N numbers of array a number is a X-number if it is divisible by atleast one other number in the array. Program to find how many such numbers exists in an given array
example 1 : in array [1,2,3] , number of x-numbers is 2 ( 2 and 3 as they are divisible by number 1 )
example 2 : in array [2,3,5,8] , number of x-numbers is 1 ( 8 is divisible by 2 )
example 3 : in array [2,3,6,12] , number of x-numbers is 2 ( 6 is divisible by 2 and 3 , 12 is divisible by 2 and 3 and 6 )
I am using the below code, but i want to optimize it in a way if the array size increase the performance should not hamper :
$arr = array(2,3,6,12);
$count = 0;
function check_special_num($tnum, $tarr){
sort($tarr);
for($i=0;$i<sizeof($tarr);$i++){
if( $tnum % $tarr[$i] == 0 ){
return true;
}
}
return false;
}
for($i=0;$i<sizeof($arr);$i++){
$temp = $arr;
$num = $arr[$i];
array_splice($temp, $i, 1);
if( check_special_num( $num, $temp ) ){
$count += 1;
}
}
echo $count;
Coding language is PHP

Answer 1

It might be faster this way:
$arr = array(2,3,6,12);
function x_numbers_count($arr) {
$count = 0;
sort($arr);
foreach ($arr as $i => $number) {
for ($j = 0; $j < $i; $j++) {
if ($number % $arr[$j] == 0) {
$count++;
break;
}
}
}
return $count;
}
echo x_numbers_count($arr);
The main differences, which can be expected to improve performance:
the array is sorted only once, before beginning to work (this could also improve your own method, without changing anything else)
the search loop stops as soon as it is to reach the current investigated number
less variables are used