PHP - 在单个树结构上的递归数组合并，显示所有排列

Question

我在这样的多维数组中有一个数据树：

[0] => Array
    (
        [0] => 14
        [1] => 12
        [2] => Array
            (
                [0] => Array
                    (
                        [0] => 16
                        [1] => 13
                    )

                [1] => Array
                    (
                        [0] => 13
                    )

                [2] => Array
                    (
                        [0] => 16
                    )

            )

    )

[1] => Array
    (
        [0] => 12
    )

...我正在尝试编写一个输出此算法的算法：

[0] => Array
    (
        [0] => 14
        [1] => 12
        [2] => 16
        [3] => 13
    )

[1] => Array
    (
        [0] => 14
        [1] => 12
        [0] => 13
    )

[2] => Array
    (
        [0] => 14
        [1] => 12
        [0] => 16
    )

[3] => Array
    (
        [0] => 12
    )

我可以提出的最佳方法是递归数组合并，它显示通过给定数组树的所有路径的所有可能的合并数组排列。

我最接近的是：

[0] => Array
    (
        [0] => 14
        [1] => 12
        [2] => 16
        [3] => 13
    )

[1] => Array
    (
        [0] => 13
    )

[2] => Array
    (
        [0] => 16
    )

[3] => Array
    (
        [0] => 12
    )

输出的代码是：

$return = [];

function enumerateTreePaths($arr, &$return, $path_k = 0)
{
    foreach ($arr as $el)
    {
        if (is_array($el))
        {
            foreach($el as $i)
            {
                enumerateTreePaths($i, $return, $path_k++);
            }
        }
        else
        {
            $return[$path_k][] = $el;
        }
    }
}

为粗心的命名约定道歉。递归==大脑融化。

我显然需要在那里进行某种数组合并，但未能找到精确的逻辑。

感谢您的任何意见。

哦，这实际上也包含在foreach中;

    foreach ($trees as $tree)
    {
        $return = [];

        enumerateTreePaths($tree, $return);

        $paths = array_merge($paths, $return);
    }