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 1:
Input: root = [5,2,-3] Output: [2,-3,4]
Example 2:
Input: root = [5,2,-5] Output: [2]
Constraints:
- The number of nodes in the tree is in the range
[1, 104]. -105 <= Node.val <= 105
[Hash Table] [Tree] [Depth-First Search] [Binary Tree]
- Subtree of Another Tree (Easy)
- Count Nodes Equal to Sum of Descendants (Medium)