Find Largest Value in Each Tree Row

Find Largest Value in Each Tree Row is a Medium Data Structures and Algorithms interview problem you can solve, run and submit on Thita.ai. It belongs to the Tree Traversal Patterns (DFS & BFS) pattern, in the Level Order Traversal subpattern.

Problem statement

Given the root of a binary tree, return an array of the largest value in each row of the tree (0-indexed).

Example 1:

Input: root = [1,3,2,5,3,null,9] Output: [1,3,9]

Example 2:

Input: root = [1,2,3] Output: [1,3]

Constraints:

- The number of nodes in the tree will be in the range [0, 104].

- -231 <= Node.val <= 231 - 1

Topics and companies

Topics: Tree, Depth-First Search, Breadth-First Search, Binary Tree.

Reported in interviews at Facebook.

How to practise Find Largest Value in Each Tree Row on Thita.ai

Starter code is provided in C, C#, C++, Go, Java, JavaScript and Python. Your solution runs against 5 test cases for this problem, with the AI coach available for a hint when you are stuck rather than a finished answer. The reference solution runs in O(n) time and O(h) space.

Open Find Largest Value in Each Tree Row in the code editor, or read the Find Largest Value in Each Tree Row editorial for a worked solution with its approach and complexity analysis.

Where Find Largest Value in Each Tree Row sits in the DSA pattern sheet

• Tree Traversal Patterns (DFS & BFS) pattern guide
• Level Order Traversal subpattern
• The full DSA patterns sheet
• All coding practice problems

Problems related to Find Largest Value in Each Tree Row

Other problems that use the same Level Order Traversal and Tree Traversal Patterns (DFS & BFS) techniques:

• Binary Tree Level Order Traversal — Medium, same subpattern
• Binary Tree Right Side View — Medium, same subpattern
• Binary Tree Zigzag Level Order Traversal — Medium, same subpattern
• Maximum Level Sum of a Binary Tree — Medium, same subpattern
• All Nodes Distance K in Binary Tree — Medium, same pattern
• Balanced Binary Tree — Easy, same pattern