Question

B-tree of order n is a order-n multiway tree in which each non-root node contains __________

(a) at most (n – 1)/2 keys

(b) exact (n – 1)/2 keys

(c) at least 2n keys

(d) at least (n – 1)/2 keys

Enquiry is from B-Trees in portion B-Trees of Data Structures & Algorithms I

This question was addressed to me during an interview for a job.

Answer 1

Right choice is (d) at least (n – 1)/2 keys

The explanation is: A non-root node in a B-tree of order n contains at least (n – 1)/2 keys. And contains a maximum of (n – 1) keys and n sons.