515\. Find Largest Value in Each Tree Row

Medium

Given the `root` of a binary tree, return _an array of the largest value in each row_ of the tree **(0-indexed)**.

**Example 1:**

![](https://assets.leetcode.com/uploads/2020/08/21/largest_e1.jpg)

**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 <code>[0, 10<sup>4</sup>]</code>.
*   <code>-2<sup>31</sup> <= Node.val <= 2<sup>31</sup> - 1</code>