Find path between two nodes in a binary tree

## Problem Given a binary tree and two target nodes `a` and `b`, return the **simple path** from `a` to `b` (inclusive) as an ordered list of node values. - The path should list nodes in the order you would visit them when traveling from `a` to `b` along parent/child links. - You may assume the tree nodes have fields like `val`, `left`, and `right`. ### Example 1 Tree: ``` 1 / \ 2 3 ``` Input: `a = 2`, `b = 3` Output: `[2, 1, 3]` ### Example 2 Tree: ``` 1 / \ 2 3 / \ 6 5 / \ 7 8 ``` Input: `a = 3`, `b = 5` Output: `[3, 1, 2, 5]` ## Requirements - Define what your function receives for `a` and `b` (e.g., node references/pointers, unique IDs, or values). - Handle cases where one node is the ancestor of the other. - Clarify behavior if one or both targets are not present (e.g., return empty list or error). ## Follow-ups 1. **Duplicate values:** If the tree can contain duplicate values, how does your approach change? What should be used to identify `a` and `b`? 2. **BST variant:** If the tree is a Binary Search Tree, what (if anything) changes in: - the algorithm, - and the time complexity (compared to a general binary tree)?