Compute shortest path between tree nodes
Company: Snowflake
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Onsite
You are given the root of a binary tree with unique integer values and two target values u and v. Return the sequence of node values along the shortest path between u and v. If either node does not exist, return an empty list. Solve in O(n) time and O(h) extra space by finding the lowest common ancestor and reconstructing the path from u and v to the LCA. Provide either iterative or recursive implementations and analyze complexity.
Quick Answer: This question evaluates a candidate's ability to work with binary tree algorithms, including tree traversal, lowest common ancestor identification, path reconstruction, and asymptotic complexity analysis.