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