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]
Example 3:
Input: root = [1] Output: [1]
Example 4:
Input: root = [1,null,2] Output: [1,2]
Example 5:
Input: root = [] Output: []
Constraints:
- The number of nodes in the tree will be in the range
[0, 104]. -231 <= Node.val <= 231 - 1