You will be given a definition of a task first, then some input of the task.
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.

[51, 478, 19, 347, 243, 112, 95, 326, 321, 23, 230, 161, 74, 99, 409, 440, 405, 377, 317, 481]
Output:
[51, 478, 481, 347, 243, 112, 95, 326, 321, 23, 230, 161, 74, 99, 409, 440, 405, 377, 317, 19]