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: From the right side, you see node 1 at level 0, node 3 at level 1, and node 4 at level 2.
Example 2:
Input: root = [1, null, 3]
Output: [1, 3]
Example 3:
Input: root = []
Output: []
[0, 100]-100 <= Node.val <= 100