Binary Tree Right Side View

Medium · Trees

You are given the root of a binary tree. Imagine standing to the right of the tree looking at it from that side; return the values of the nodes you can see, ordered from the top of the tree to the bottom. A node is visible if it is the last (rightmost) node encountered at its depth level during a left-to-right scan.

Examples

Input:  root = [1,2,3,null,5,null,4]
Output: [1,3,4]
Why:    Level 0 shows 1, level 1 shows 3 (rightmost of 2,3), level 2 shows 4 (rightmost of 5,4).

Input:  root = [1,2,3,4,null,null,null,5]
Output: [1,3,4,5]
Why:    Each level's rightmost visible node from top to bottom is 1, 3, 4, then 5.

Input:  root = []
Output: []
Why:    An empty tree has no visible nodes.

Constraints

0 <= number of nodes <= 100, -100 <= Node.val <= 100

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Practise Binary Tree Right Side View

This statement is written for CodeSpeek. The problem is part of the NeetCode 150 list; Watch NeetCode's explanation of Binary Tree Right Side View. Reference solutions from the NeetCode repository (MIT) are used to verify our tests.