Nested array to single array keeping the parents - php

Question

The problem is to change a tree structure to a simple array structure, in which each child has the parents who belongs to, the example is a directories and files structure, but I'm looking for a generic solution.
If the writing is bad, feel free to improve it.
Any help is welcome.
Example.
$array_1=array(
'f1' =>
array(
'f2' =>array('file1.php','file2.php'),
'f3' =>array('file3.php','file4.php'),
'f4' =>
array(
'fol5'=>
array('fileAA.php','fileBB.php')
,
'fileDD.php'
),
),
'f2' =>
array(
'f2' =>array('file1.php','file2.php'),
'f3' =>array('file3.php'),
)
);
The result should be like this:
/*
0 => '/f1/f2/file1.php',
1 => '/f1/f2/file2.php',
2 => '/f1/f3/file3.php',
3 => '/f1/f3/file4.php',
4 => '/f1/f4/fol5/fileAA.php',
5 => '/f1/f4/fol5/fileBB.php',
6 => '/f1/f4/fileDD.php',
7 => '/f2/f2/file1.php',
8 => '/f2/f2/file2.php',
9 => '/f2/f3/file3.php',
*/

Answer 1

here is simple recursive function:
function tree2array($input, &$output, $prefix = '')
{
foreach ($input as $i => $v)
if (is_array($v))
tree2array($v, $output, $prefix.'/'.$i);
else
$output[] = $prefix.'/'.$v;
}
usage:
tree2array($array_1, $array2);
output:
print_r($array2);
Array (
[0] => /f1/f2/file1.php
[1] => /f1/f2/file2.php
[2] => /f1/f3/file3.php
[3] => /f1/f3/file4.php
[4] => /f1/f4/fol5/fileAA.php
[5] => /f1/f4/fol5/fileBB.php
[6] => /f1/f4/fileDD.php
[7] => /f2/f2/file1.php
[8] => /f2/f2/file2.php
[9] => /f2/f3/file3.php )

Answer 2

I made an alternative solution using SPL
$arrayiter = new RecursiveArrayIterator($array_1);
$iteriter = new RecursiveIteratorIterator($arrayiter,RecursiveIteratorIterator::CHILD_FIRST);
foreach ($iteriter as $key => $value) {
$this_depth = $iteriter->getDepth();
if(!is_array($value)){
$array_2[] = '/'.$value;
$level[]=$this_depth;
}
foreach($array_2 as $key2 => $value2){
if($this_depth < $level[$key2]){
$level[$key2] = $this_depth;
$array_2[$key2] = '/'.$key.$value2;
}
}
}
echo'<pre>';
print_r($array_2);
echo'</pre>';