Is Maximum Depth of Binary Tree easy or hard?

Maximum Depth of Binary Tree is classified as an Easy problem on most coding platforms. It focuses on fundamental tree traversal concepts and is often used to introduce DFS recursion or BFS level-order traversal.

Maximum Depth of Binary Tree Python Java solution

In Python or Java, the typical solution uses recursion: return 0 for a null node, otherwise return 1 plus the maximum depth of the left and right children. BFS solutions use a queue to process nodes level by level and increment the depth after finishing each level.

How to solve Maximum Depth of Binary Tree in O(n)?

Traverse the tree once using either DFS or BFS. With DFS, recursively compute the maximum depth of left and right children and return 1 + max(left, right). With BFS, process nodes level by level using a queue and count the number of levels until the queue becomes empty.

What is the best approach for Maximum Depth of Binary Tree?

Recursive Depth-First Search (DFS) is the most common and clean approach. For each node, compute the depth of the left and right subtrees and return 1 plus the larger value. This visits every node once, giving O(n) time complexity and O(h) space complexity for the recursion stack.

Is Maximum Depth of Binary Tree asked at Google Amazon Meta?

Maximum Depth of Binary Tree is a classic tree traversal problem frequently used in technical interviews. Variants and related tree depth problems have appeared in interviews at companies such as Amazon, Google, Meta, and Microsoft because they test understanding of recursion and tree traversal.

What data structure is used in Maximum Depth of Binary Tree?

The problem uses a binary tree as the primary data structure. Solutions typically rely on recursion with the call stack for DFS or a queue for BFS level-order traversal.

What is the time complexity of Maximum Depth of Binary Tree?

The time complexity is O(n) because every node in the binary tree must be visited at least once to determine the deepest path. Both DFS and BFS implementations process each node exactly once.

Description Solution Video 16:43

104. Maximum Depth of Binary Tree

Easy78.6% acceptance17 companies

Given the root of a binary tree, return its maximum depth.

A binary tree's maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Example 1:

Input: root = [3,9,20,null,null,15,7]
Output: 3

Example 2:

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

Constraints:

The number of nodes in the tree is in the range [0, 10⁴].
-100 <= Node.val <= 100

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104. Maximum Depth of Binary Tree

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