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: [15, 294, 79, 413, 414, 445, 53, 123, 18, 459, 248, 142, 395, 351, 191, 317, 455, 358, 187, 473]
A: 
[473, 294, 79, 413, 414, 445, 53, 123, 18, 459, 248, 142, 395, 351, 191, 317, 455, 358, 187, 15]