Small balanced tree
Input
compute_height(TreeNode(1, TreeNode(2), TreeNode(3)))
Output
2
Root plus one level of children -> height is 2.
Full lesson preview
Compute tree height
Find the height of a binary tree (empty tree height = 0).
Python practice8 minTrees & Binary TreesBeginnerLast updated March 29, 2026
Problem statement
Given the root of a binary tree, compute its height. Define the height as the number of nodes on the longest root-to-leaf path. For an empty tree (root is None), the height is 0.
You should implement compute_height(root) that returns an integer height.
Task
Implement a function that returns the height (maximum number of nodes from root to any leaf) of a binary tree.
Examples
Input format
A single argument: root (TreeNode or None).
Output format
An integer representing the tree height.
Constraints
- Number of nodes up to a few thousand (recursive or iterative solutions acceptable).
- You may assume TreeNode values are integers but values do not affect height.
Samples
Sample 1
Input
compute_height(None)
Output
0
Empty tree has height 0.