快速排序

quickSort.php

<?php
function quickSort($array) {
  if(count($array) <= 1){
    return $array;
  }
  $mid = $array[0];
  $right_array = array();
  $left_array = array();
  for($i = 1;$i < count($array); $i++) {
    if($array[$i] > $mid) {
        $right_array[] = $array[$i];
    } else {
        $left_array[] = $array[$i];
    }
  }
    $right_array = quickSort($right_array);
    $left_array = quickSort($left_array);
    $array = array_merge($left_array, array($mid), $right_array);
    return $array;
}
$num = [8,4,5,0,3,4,2];
var_dump(quickSort($num));