Converting arrays into another format (PHP)

Question

Hi.. i want to convert this array

 Array
(
    [2] => Array
        (
        )
    [4] => Array
        (
            [12] => Array
                (
                )
            [13] => Array
                (
                 [16] => Array
                    (
                    )
                )
        )
    [5] => Array
        (
        )
    [10] => Array
        (
        )
    [14] => Array
        (
        )
)

into this format

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

    [5] => 5
    [10] => 10
    [14] => 14
)

can anybody help? thanks. [continued 16Mar2010]

its not

[2] =>array

but

[2] => 2

if it is an array with 1 child or more, then it would be [4] => Array([12]=>12

input data is

$a = array(2 => array(), 4 => array(12 => array(), 13 => array(16 => array())), 5 => array(), 10 => array(), 14 => array());

Answer 1

<?php

$arr = array ( "2" => array ( ) , "4" => array ( "12" => array () , 13 => array () , ) , 5 => array () , 10=> array () , 14 => array() );

foreach ( $arr as $key => $val )
{
global $arr ;
if ( empty ( $val ) )
{
  unset($arr[$key]);
  $arr[$key]=$key;
}
}

print_r  ( $arr) ;

?>

Answer 2

foreach($ary as $k => $v)
  $result[$k] = $v ? array_keys($v) : $k;

untested