Pair with difference K
Count unordered index pairs with absolute difference exactly K, handling duplicates correctly.
Set intersection size
Count how many distinct values appear in both of two given lists.
Symmetric Difference
Write a function that computes the symmetric difference of two lists, returning a sorted list of unique elements.
Disjoint Set Check
Check if two lists are disjoint by verifying they have no common elements.
Subset of another set
Write a function that checks if every element of one set is contained in another.
Frequency sort descending
Write a function that sorts a list by frequency descending while preserving original order for ties.
Count Pairs with Sum
Implement a function that counts the number of distinct pairs in a list summing to a target.
Hash map merge
Write a function that merges two dictionaries recursively, combining values and preserving structure.
Ransom Note Builder
Given two strings, determine if the ransom note can be formed from the words in the magazine.
Longest Harmonious Subsequence
Given a list of integers, find the length of the longest harmonious subsequence where the difference between maximum and minimum values is exactly 1.
Group by Department
Implement a function that groups a list of employee dictionaries by department, returning a dictionary keyed by department with lists of employee dictionaries.
Revenue by Month
Write a function that groups a list of (date, amount) pairs by year-month and returns total revenue per month as a sorted dictionary.
Pivot sales by product
Write a function that pivots sales records into a dictionary keyed by product with monthly totals.
Showing 25–37 of 37 challenges · Dicts & Sets
Dicts & Sets — Python coding challenges
What you will find here
This page lists dicts & sets 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.