Binary Tree Rightmost Node (Right Side View)

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.

• Essentially: For every level, pick the last node.

We can use BFS (Level Order Traversal).

1. Process the tree level by level.
2. For each level, the last node in the queue (before moving to the next level) is the rightmost node.
3. Add that node's value to our result list.

Watch BFS collecting the last element of every level.