199\. Binary Tree Right Side View

Medium

Given the `root` of a binary tree, imagine yourself standing on the **right side** of it, return _the values of the nodes you can see ordered from top to bottom_.

**Example 1:**

![](https://assets.leetcode.com/uploads/2021/02/14/tree.jpg)

**Input:** root = [1,2,3,null,5,null,4]

**Output:** [1,3,4] 

**Example 2:**

**Input:** root = [1,null,3]

**Output:** [1,3] 

**Example 3:**

**Input:** root = []

**Output:** [] 

**Constraints:**

*   The number of nodes in the tree is in the range `[0, 100]`.
*   `-100 <= Node.val <= 100`