Question

Statement 1: When a node is split during insertion, the middle key is promoted to the parent as well as retained in right half-node.

Statement 2: When a key is deleted from the leaf, it is also deleted from the non-leaf nodes of the tree.

(a) Statement 1 is true but statement 2 is false

(b) Statement 2 is true but statement 1 is false

(c) Both the statements are true

(d) Both the statements are false

I'd like to ask this question from B-Trees in section B-Trees of Data Structures & Algorithms I

The question was posed to me by my college director while I was bunking the class.

Answer 1

Correct choice is (a) Statement 1 is true but statement 2 is false

Easy explanation - During the split, the middle key is retained in the right half node and also promoted to parent node. When a key is deleted from the leaf, it is retained in non-leaves, because it can be still a valid separator between keys in nodes below.