Guys most of the questions are above, here I'm gonna share the question I failed, as I promised the interviewer that I'm gonna solve it, I just needed more time.
The most difficult question is the following:
we have this array:
$input = [
'item/id' => 'my_id',
'item/title' => 'my_title',
'item/group1/val1' => 'my_val1',
'item/group1/val2' => 'my_val2',
'summary' => 'xyz',
'item/group1/val3' => 'my_val3',
];
We need to convert it to :
Array (
[item] => Array (
[id] => my_id
[title] => my_title
[group1] => Array (
[val1] => my_val1
[val2] => my_val2
[val3] => my_val3
)
)
[summary] => xyz
)
This is using PHP.