Question

What is the general form of Shell’s increments?

(a) 1,2,3,…,n

(b) 1,3,7,….,2k-1

(c) 1,3,5,7,….,k-1

(d) 1,5,10,15,…, k-1

I have been asked this question by my college professor while I was bunking the class.

Query is from Shell sort topic in division Sorting of Data Structures & Algorithms II

Answer 1

Correct choice is (b) 1,3,7,….,2k-1

Easy explanation - Shell’s increments are of the form 1,3,7,….,2k-1. The key difference is that the consecutive elements have no common factors.