We’re given an array of unique integers. We’d like to sort the array such that the following conditions are true:
- The maximum number is the very last number in the array
- Numbers should alternate between increasing and decreasing.

Examples:
Input: [1, 5, 6, 2, 3]
Example valid outputs: [2, 1, 5, 3, 6], [5, 1, 3, 2, 6], [3, 1, 5, 2, 6]