Recursive PHP Tree (permutations) - php

Question

I'm looking to write a function which creates all permutation of a list of arrays (The list is dynamical). Now I found 2 articles, http://dannyherran.com/2011/06/finding-unique-array-combinations-with-php-permutations/ and Finding cartesian product with PHP associative arrays. But I don't want to store them as multiple arrays, I want to add each array to each possibility so I can use them later.
In fact I want to multiply each array with the other.
For example:
$array = array(
array(
1,
2
),
array(
'A',
'B',
'C'),
array(
'I',
'II')
);
In this form:
Array
(
[0] => Array
(
[0] => 1
[1] => Array
(
[0] => Array
(
[0] => A
[1] => Array
(
[0] => I
[1] => II
)
)
[1] => Array
(
[0] => B
[1] => Array
(
[0] => I
[1] => II
)
)
[2] => Array
(
[0] => C
[1] => Array
(
[0] => I
[1] => II
)
)
)
)
[1] => Array
(
[0] => 2
[1] => Array
(
[0] => Array
(
[0] => A
[1] => Array
(
[0] => I
[1] => II
)
)
[1] => Array
(
[0] => B
[1] => Array
(
[0] => I
[1] => II
)
)
[2] => Array
(
[0] => C
[1] => Array
(
[0] => I
[1] => II
)
)
)
)
)
I think this big example made my problem clear. For this type of array I created a function:
foreach ($array[1] as $value) {
$return1[] = array($value, $array[2]);
}
foreach ($array[0] as $value) {
$return[] = array($value, $return1);
}
print_r($return);
Now I want to create this function inside a recursive function (so it becomes dynamical) but I got stuck. I wanted to pass the amount of arrays to the function and then iterate.
function createTree($array, $loops=3){
$b = $array[$loops-2];
foreach ($b as $v) {
$return[] = array($v, createTree($return, $loops-1));
}
print_r($return);
}
Maybe there is a total other solution to multiply the arrays? But the function which isn't recursive is easy for me, but making it recursive...
Thanks for your help

Answer 1

function createTree($array){
switch(count($array)) {
case 0:
die('Illegal argument.');
case 1:
return $array[0];
default:
$lastArray = array_pop($array);
$subArray = createTree($array);
foreach ($lastArray as $item) {
$return[] = array($item, $subArray);
}
return $return;
}
}
var_dump(createTree(array_reverse($array)));