Find mode in a trinary search tree

You are given the root of a **trinary search tree** where each node has up to three children: ```text class Node { int val; Node left; // all values < val Node middle; // all values = val Node right; // all values > val } ``` Assume the tree is intended to satisfy the ordering rules above. ## Task Return the **mode(s)** of the tree: the value(s) that occur most frequently among all nodes. - If there is one mode, return a single-element list. - If multiple values tie for highest frequency, return **all** such values (in any order). ## Constraints (typical) - Number of nodes `n` can be large (e.g., up to `10^5`). - Values can be any 32-bit signed integers. ## Follow-up How would your approach change if the tree is **broken** (i.e., it may not respect the `<`, `=`, `>` constraints), but you still must return the correct mode(s)?