数组排序自定义算法使用(PHP)

http://sandbox.onlinephpfunctions.com/code/971f4a6c9dfe80ec6277dd89653ea160af3c68e4

我找不到解决办法。。请帮助返回更改的数组

密码

<?php
    function bell_sort($arr, $head, $tail, $queue) {


     if($head != $tail){
         $min = $arr[$head];
         $min_index = $head;

         for($i = $head; $i <= $tail; ++$i){
             if($arr[$i] < $min){
                 $min = $arr[$i];
                 $min_index = $i;
             }
         }

         if($queue){
             $tmp = $arr[$head];
             $arr[$head] = $arr[$min_index];
             $arr[$min_index] = $tmp;
             $head++;
         }else{
             $tmp = $arr[$tail];
             $arr[$tail] = $arr[$min_index];
             $arr[$min_index] = $tmp;
             $tail--;
         }

        bell_sort($arr, $head, $tail, !$queue);  

        }else{
         return $arr;
        }


     }


    $n = 10;

    for($i = 0; $i < $n; ++$i){
        $arr[$i] = rand(0, 100);
    }

    $head = 0;
    $tail = count($arr) - 1;
    $queue = 1; 
    $new_arr = bell_sort($arr, $head, $tail, $queue);

    var_dump($new_arr);