It says Given an n x n array.

And I have no idea what answer you expect for your array.

Nice solution, but doesn't work with array like this:
array = [[1, 2, 3],
[10, 11, 12, 4],
[9, 15, 14, 13, 5],
[8, 7, 6]]

Perhaps such ugly arrays weren't implied, but anyway they still can be "snailed" :-)