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: [329, 163, 460, 187, 365, 470, 317, 350, 354, 431, 378, 271, 223, 294, 48, 118, 450, 151, 337, 284]
Output:
[329, 163, 460, 187, 365, 48, 317, 350, 354, 431, 378, 271, 223, 294, 470, 118, 450, 151, 337, 284]