Definition: In this task, you are given a list of unique integers you need to swap the positions of maximum and minimum element in the list and return the updated list.
Input: [275, 398, 432, 305, 25, 124, 329, 12, 422, 466, 295, 96, 29, 365, 427, 389, 284, 397, 13, 99]

[275, 398, 432, 305, 25, 124, 329, 466, 422, 12, 295, 96, 29, 365, 427, 389, 284, 397, 13, 99]