Coding (Algo)

Find the Shared Ancestor

Algorithm: Lowest common ancestor Difficulty: Medium Time: 35 minutes

Goal

Return the value of the lowest common ancestor of p and q, or null when either value is not reachable from the root.

What this task practices

Find the Shared Ancestor is a coding (algo) interview exercise that trains prompt interpretation, explicit assumptions, a concrete response, and a clear explanation of tradeoffs. The catalog marks it as medium difficulty. It focuses on Technical Reasoning, Testing, Validation. The signed-in workspace provides the tools for the round and evaluates the attempt against task-specific criteria. Reference solutions, hidden checks, evaluator instructions, and candidate work remain private.