Alien Dictionary Order
Given a sorted list of words in an alien language, derive the order of its unique letters.
Graph Valid Tree
Determine if n nodes and an edge list form a valid tree (connected and acyclic).
Showing 2 challenges · medium · Graphs & Graph Algorithms
Graphs & Graph Algorithms — Python coding challenges
What you will find here
This page lists graphs & graph 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.