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.

[77, 481, 445, 178, 275, 58, 42, 168, 92, 136, 390, 498, 133, 333, 396, 85, 243, 283, 323, 322]
[77, 481, 445, 178, 275, 58, 498, 168, 92, 136, 390, 42, 133, 333, 396, 85, 243, 283, 323, 322]