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: [131, 212, 431, 43, 122, 473, 421, 142, 171, 252, 78, 68, 414, 329, 61, 283, 346, 284, 204, 381]

[131, 212, 431, 473, 122, 43, 421, 142, 171, 252, 78, 68, 414, 329, 61, 283, 346, 284, 204, 381]