Given an n x n array, return the array elements arranged from outermost
elements to the middle element, traveling clockwise.
array = [[1,2,3],
[4,5,6],
[7,8,9]]
snail(array) #=> [1,2,3,6,9,8,7,4,5]
For better understanding, please follow the numbers of the next array consecutively:
array = [[1,2,3],
[8,9,4],
[7,6,5]]
snail(array) #=> [1,2,3,4,5,6,7,8,9]
This image will illustrate things more clearly:
- The idea is not sort the elements from the lowest value to the highest; the idea is to traverse the 2-d array in a clockwise snail shell pattern.
- The 0x0 (empty matrix) is represented as
[[]]