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.

[265, 209, 433, 482, 412, 249, 19, 456, 256, 334, 50, 223, 458, 135, 65, 282, 309, 405, 274, 430]
[265, 209, 433, 19, 412, 249, 482, 456, 256, 334, 50, 223, 458, 135, 65, 282, 309, 405, 274, 430]