Spiral Matrix Traversal

Problem Description

Given a 2D array (matrix), write a function that returns all the elements of the matrix in spiral order (clockwise). This means starting from the top-left element and moving right, then down, then left, then up, and repeating this process until all elements have been included in the result.

For example, given the matrix:

[
  [ 1,  2,  3, 4],
  [ 5,  6,  7, 8],
  [ 9, 10, 11,12]
]

The spiral order is: [1, 2, 3, 4, 8, 12, 11, 10, 9, 5, 6, 7].

Groundhog Day (February 2nd) is a time for new beginnings and looking at things from a different perspective. Use this opportunity to make sure your algorithm covers all edge cases, just as we re-examine the seasons every year!

Function Signature and I/O Details

• Input: A two-dimensional list (matrix) of integers with dimensions m x n, where m and n are greater than 0.
• Output: A list (or equivalent) of integers representing the matrix elements in spiral order.

Example:

Input:

[[1, 2, 3],
 [4, 5, 6],
 [7, 8, 9]]

Output:

[1, 2, 3, 6, 9, 8, 7, 4, 5]