Count pairs with given difference
Count how many unordered pairs in a list have a given absolute difference using an efficient approach.
Previous Smaller Element
Find the nearest previous index with a smaller value for every element in an array.
Union Find Class
Implement a UnionFind class with find and union operations supporting path compression and union by size.
Delete Old Records
Filter a list of records by removing those with a date older than a given cutoff date.
Argsort Indices
Implement a function that returns the indices that would sort a list of integers, with ties broken by original order.
Showing 5 challenges · easy · 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.