Array permutations
Question
Given an array, arr, of unique integers, write a function to find all possible permutations.
For example:
Input : arr = [4,5,6]
Output : [[4, 5, 6],
[4, 6, 5],
[5, 4, 6],
[5, 6, 4],
[6, 4, 5],
[6, 5, 4]]
Input : arr = [10,14,15]
Output : [[10, 14, 15],
[10, 15, 14],
[14, 10, 15],
[14, 15, 10],
[15, 10, 14],
[15, 14, 10]]