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: [477, 200, 377, 405, 450, 137, 333, 139, 195, 52, 445, 154, 61, 63, 441, 455, 308, 354, 19, 340]
Example Output: [19, 200, 377, 405, 450, 137, 333, 139, 195, 52, 445, 154, 61, 63, 441, 455, 308, 354, 477, 340]

Example Input: [157, 298, 54, 206, 237, 485, 440, 282, 247, 450, 28, 280, 474, 496, 379, 390, 392, 217, 422, 165]
Example Output: [157, 298, 54, 206, 237, 485, 440, 282, 247, 450, 496, 280, 474, 28, 379, 390, 392, 217, 422, 165]

Example Input: [128, 249, 389, 83, 380, 314, 51, 289, 383, 247, 133, 336, 391, 41, 312, 497, 306, 349, 255, 488]
Example Output:
[128, 249, 389, 83, 380, 314, 51, 289, 383, 247, 133, 336, 391, 497, 312, 41, 306, 349, 255, 488]