Instructions: 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: [33, 439, 485, 138, 228, 443, 339, 421, 118, 21, 215, 182, 220, 265, 186, 153, 160, 43, 213, 256]
Output:
[33, 439, 21, 138, 228, 443, 339, 421, 118, 485, 215, 182, 220, 265, 186, 153, 160, 43, 213, 256]