the-spiraling-box

The 'spiraling' box

Task

Given two positive integers m (width) and n (height), fill a two-dimensional list (or array) of size m-by-n in the following way:

• (1) All the elements in the first and last row and column are 1.

• (2) All the elements in the second and second-last row and column are 2, excluding the elements from step 1.

• (3) All the elements in the third and third-last row and column are 3, excluding the elements from the previous steps.

• And so on ...

Examples

create_box(5, 8) should return

[[1, 1, 1, 1, 1],
 [1, 2, 2, 2, 1],
 [1, 2, 3, 2, 1],
 [1, 2, 3, 2, 1],
 [1, 2, 3, 2, 1], 
 [1, 2, 3, 2, 1],
 [1, 2, 2, 2, 1],
 [1, 1, 1, 1, 1]]

create_box(10, 9) should return

[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
 [1, 2, 2, 2, 2, 2, 2, 2, 2, 1],
 [1, 2, 3, 3, 3, 3, 3, 3, 2, 1], 
 [1, 2, 3, 4, 4, 4, 4, 3, 2, 1], 
 [1, 2, 3, 4, 5, 5, 4, 3, 2, 1], 
 [1, 2, 3, 4, 4, 4, 4, 3, 2, 1], 
 [1, 2, 3, 3, 3, 3, 3, 3, 2, 1], 
 [1, 2, 2, 2, 2, 2, 2, 2, 2, 1], 
 [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]]