Question

If a list contains ’n’ number of elements and all the elements are by default sorted in ascending order, how many comparisons will be required during 1^st pass of bubble sort to arrange the list in ascending order?

• A. 0
• B. 1
• C. n - 1
• D. n

Answer 1

The Correct Option is C

Bubble Sort operates by iteratively comparing adjacent elements and exchanging them if they are in the incorrect order. In the initial pass, comparisons are made between all elements except the last, as this guarantees the largest element settles at the list's end.

Consider a list containing 'n' elements ordered ascendingly.

• The 1^st pass executes comparisons between the 1^st and 2^nd elements, then the 2^nd and 3^rd, continuing until the (n-1)^th element is compared with the n^th element.
• Consequently, the 1^st pass involves exactly (n-1) comparisons.

Therefore, for a list of 'n' elements, the first pass of Bubble Sort requires n - 1 comparisons.