Binary Tree Right Side View
Difficulty: Medium
Category: DSA
Topics: Tree, Depth-First Search, Breadth-First Search, Binary Tree
Asked at: Facebook, Amazon, ByteDance, Bloomberg, Microsoft
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:**
**Input:** root = [1,2,3,null,5,null,4]
**Output:** [1,3,4]
**Explanation:**
**Example 2:**
**Input:** root = [1,2,3,4,null,null,null,5]
**Output:** [1,3,4,5]
**Explanation:**
**Example 3:**
**Input:** root = [1,null,3]
**Output:** [1,3]
**Example 4:**
**Input:** root = []
**Output:** []
**Constraints:**
- The number of nodes in the tree is in the range `[0, 100]`.
- `-100 <= Node.val <= 100`