Question

This is a interview question: given an array of integers find the max. and min. using minimum comparisons.

Obviously, I can loop over the array twice and use ~2n comparisons in the worst case but I would like to do better.

Answer 1

1. Pick 2 elements(a, b), compare them. (say a > b)
2. Update min by comparing (min, b)
3. Update max by comparing (max, a)

This way you would do 3 comparisons for 2 elements, amounting to 3N/2 total comparisons for N elements.