Binary Tree Right Side View (Build tree + write your own test cases)

Problem: Binary Tree Right Side View (Build the tree + write your own test cases) Given the root root of a binary tree, return the values of the nodes you can see when looking at the tree from the right side, ordered from top to bottom. Requirements You need to define the binary tree node structure yourself (e.g., TreeNode) and build the tree from the input. Implement the algorithm and write your own test cases to validate correctness. Suggested Input Format Use a level-order array representation of the binary tree, e.g. [1,2,3,null,5,null,4], where null indicates a missing node. Output Format Return an integer array representing the right side view. Constraints Number of nodes n: 0 <= n <= 10^4 Node value range: -10^9 <= val <= 10^9 Example Input: [1,2,3,null,5,null,4] Output: [1,3,4] Example Input [1,2,3,null,5,null,4] Output [1,3,4]