BFS level-order traversal
Return the level-order traversal of a binary tree as a list of lists.
Employee Hierarchy
Build an employee hierarchy tree and compute the total number of direct and indirect reports for each employee.
Path Sum II All Paths
Return all root-to-leaf paths where the sum of node values equals a target.
Redundant Connection
Given a list of edges forming a tree plus one extra edge, return the edge that appears last in the input and creates a cycle.
Showing 4 challenges · Data Structures & Algorithms
Data Structures & Algorithms — Python coding challenges
What you will find here
This page lists data structures & algorithms 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.