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.
Q: [446, 271, 355, 181, 214, 338, 42, 398, 235, 467, 57, 92, 56, 282, 99, 222, 420, 339, 50, 472]
A: 
[446, 271, 355, 181, 214, 338, 472, 398, 235, 467, 57, 92, 56, 282, 99, 222, 420, 339, 50, 42]