# Leetcode 508 - Most Frequent Subtree Sum

Note:

• Classic recursion.
• Use map to record occurences.

Question:

Given the root of a binary tree, return the most frequent subtree sum. If there is a tie, return all the values with the highest frequency in any order.

The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself).

Example:

Code: