Question

Which is the safest method to choose a pivot element?

(a) choosing a random element as pivot

(b) choosing the first element as pivot

(c) choosing the last element as pivot

(d) median-of-three partitioning method

I got this question in an internship interview.

Question is taken from Quicksort topic in section Sorting of Data Structures & Algorithms II

Answer 1

Right choice is (a) choosing a random element as pivot

For explanation: This is the safest method to choose the pivot element since it is very unlikely that a random pivot would consistently provide a poor partition.