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467 challenges 330 easy 120 medium 17 hard

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Trees & Binary Trees easy

Preorder Traversal

Implement a function that returns the preorder traversal values of a binary tree.

binary-tree traversal recursion

Trees & Binary Trees medium

Lowest Common Ancestor in a Binary Tree

Implement a function to find the lowest common ancestor (LCA) of two nodes in a binary tree.

binary-tree dfs recursion

Trees & Binary Trees medium

Sum Root to Leaf Numbers

Given the root of a binary tree, compute the total sum of all root-to-leaf numbers.

binary-tree dfs recursion

Trees & Binary Trees medium

Binary tree left side view

Given a binary tree, return the leftmost node's value at each depth, from top to bottom.

binary-tree levels bfs

Showing 4 challenges · Trees & Binary Trees

Trees & Binary Trees — Python coding challenges

What you will find here

This page lists trees & binary trees challenges — real Python problems you solve in the browser IDE with instant test feedback. Each challenge includes a clear brief, starter code, and automated checks.

Challenges vs tutorials and quizzes

Challenges test what you can build under constraints. For guided teaching, use our Python tutorials. For quick checks, try quizzes or copy snippets from code samples.