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, 10`

.^{4}] `-2`

^{31}<= Node.val <= 2^{31}- 1