Question

How many swaps are required for reversing an array having n elements where n is an odd number?

(a) (n-1) / 2

(b) n/2

(c) (n/2) – 1

(d) (n+1)/2

My question is from Arrays Types topic in portion Arrays Types of Data Structures & Algorithms I

The question was asked in an interview.

Answer 1

The correct choice is (a) (n-1) / 2

The best I can explain: The number of swaps required for an odd element and an even element array is different because in an odd element array the position of the middle element does not need to be changed. So the number of swaps will be (n-1) / 2.