Given the root of a binary tree, return an array of the largest value in each row of the tree (0-indexed).
Example 1:
Input: root = [1,3,2,5,3,null,9]
Output: [1,3,9]
Example 2:
Input: root = [1,2,3]
Output: [1,3]
Constraints:
- The number of nodes in the tree will be in the range [0, 104].
- -231 <= Node.val <= 231 - 1
https://leetcode.com/problems/find-largest-value-in-each-tree-row/description/