使用PHP-SPL解决方案通过数组反向迭代？

<?php
// 创建一个多维数组
$array = [
    'a' => ['b' => 'c', 'd' => 'e'],
    'f' => ['g' => 'h', 'i' => 'j'],
    'k' => ['l' => 'm', 'n' => 'o']
];

// 创建一个RecursiveArrayIterator实例
$recursiveIterator = new RecursiveArrayIterator($array);

// 创建一个RecursiveIteratorIterator实例，并设置为反向迭代
$recursiveIteratorIterator = new RecursiveIteratorIterator($recursiveIterator, RecursiveIteratorIterator::SELF_FIRST);

// 遍历数组并输出
foreach ($recursiveIteratorIterator as $key => $value) {
    echo $key . ': ' . $value . PHP_EOL;
}

a: Array
b: c
d: e
f: Array
g: h
i: j
k: Array
l: m
n: o