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.

[83, 244, 378, 130, 291, 190, 199, 474, 112, 225, 109, 450, 228, 439, 143, 227, 394, 47, 203, 246]
[83, 244, 378, 130, 291, 190, 199, 47, 112, 225, 109, 450, 228, 439, 143, 227, 394, 474, 203, 246]