Final answer:
BubbleSort will make “n-1” comparisons in its first pass over an already sorted list with “n” elements, and optimally cease further iterations, leading to a best-case performance of O(n) comparisons.
Step-by-step explanation:
If a list is already sorted and the bubbleSort algorithm is applied, the number of comparisons that will be performed is related to the number of elements in the list. For a list with n elements, bubbleSort will perform n-1 comparisons in the first pass. Since the list is already sorted, no swaps will be made, and an optimized version of bubble sort can detect this and terminate early, leading to a best-case performance of O(n) comparisons overall.
In contrast, a naive bubble sort implementation may continue to make unnecessary comparisons even if no swaps are necessary. This would result in “(n-1) + (n-2) + … + 1” comparisons. The number of comparisons can be calculated using the formula n(n-1)/2. Hence, the total number of comparisons will be optimally n-1 for an already sorted list in the best-case scenario.