How to make the code work correctly with arrays?

Question

PHP

The goal is to parse the text into arrays, and collect the arrays in order
What needs to be done

Array
(
    [0] => 1 2 3 4 5
    [1] => 1 2 3 4
    [2] => 1
    [3] => 2 3 4 5
    [4] => 1 2 3
    [5] => 2 3 4
    [6] => 1 2
    [7] => 2
    [8] => 3 4 5
    [9] => 2 3
    [10] => 3 4
    [11] => 3
    [12] => 4 5
    [13] => 4
    [14] => 5
)