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819 challenges 506 easy 280 medium 33 hard

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Graphs & Graph Algorithms easy

Cycle Detection in a Directed Graph

Use DFS with a recursion stack to detect cycles in a directed graph.

graph dfs cycle

Graphs & Graph Algorithms easy

Cycle Detection in Undirected Graph

Write a function that detects if an undirected graph contains a cycle.

graph dfs cycle-detection

Graphs & Graph Algorithms easy

Clique Detection

Given an undirected graph and a list of vertices, check if every pair of distinct vertices in the list is connected by an edge.

graphs cliques adjacency-matrix

Showing 3 challenges · easy · 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.