Given an array of unique integers. Return all permutations.

Example: Array = [1, 2, 3] -->
[
  '1, 2, 3',
  '1, 3, 2',
  '2, 1, 3',
  '2, 3, 1',
  '3, 1, 2',
  '3, 2, 1'
]

Test set 1

Result:

Test set 2

Result:

Test set 3

Result:

Test set 4

Result: