Find LCA in a BST
Company: Amazon
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Technical Screen
Given the root of a binary search tree and two keys p and q, return the value of their lowest common ancestor (the deepest node whose value lies between p and q inclusive). Provide both iterative and recursive solutions, and handle the case when one or both keys may be absent by returning a sentinel or raising an error.
Quick Answer: The question evaluates understanding of binary search tree properties, the lowest common ancestor concept, and competency in implementing tree algorithms while handling absent keys via sentinel or error handling.
