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.

Example Input: [165, 22, 87, 424, 154, 434, 433, 149, 478, 426, 489, 275, 18, 320, 442, 318, 303, 104, 472, 29]
Example Output: [165, 22, 87, 424, 154, 434, 433, 149, 478, 426, 18, 275, 489, 320, 442, 318, 303, 104, 472, 29]

Example Input: [420, 59, 180, 32, 111, 494, 38, 282, 435, 432, 147, 422, 414, 260, 51, 332, 343, 207, 362, 474]
Example Output: [420, 59, 180, 494, 111, 32, 38, 282, 435, 432, 147, 422, 414, 260, 51, 332, 343, 207, 362, 474]

Example Input: [159, 271, 473, 31, 27, 126, 320, 353, 71, 432, 214, 249, 440, 266, 170, 185, 324, 398, 399, 23]
Example Output:
[159, 271, 23, 31, 27, 126, 320, 353, 71, 432, 214, 249, 440, 266, 170, 185, 324, 398, 399, 473]