Stars and Bars Count
Implement stars_and_bars_count(n, k) which returns the number of ways to put n identical items into k distinct bins, with bins allowed to be empty.
Coin Change Ways
Count the number of distinct combinations of coins that sum to a target amount.
Permutation Generator
Write a function that returns all permutations of a list of distinct integers.
Combination Generator
Write a recursive function that returns all combinations of length k from a list of distinct integers.
Generate Parentheses
Given n, generate all valid strings of n pairs of parentheses.
Letter Combinations of a Phone Number
Given a string of digits, return all possible letter combinations that the number could represent on a phone keypad.
Power set from set
Write a function to return the power set of a given list of distinct elements.
Combination Sum
Given a list of distinct positive integers and a target, return all unique combinations that sum to the target.
Showing 1–8 of 8 challenges
Guide: free Python coding challenges
Practice Python by solving problems
PythonSkillset challenges are hands-on coding exercises from beginner to advanced. Open a challenge, read the problem, write Python in the split-pane editor, and run tests with Pyodide — no install required.
How to use the arena
- Pick a category — basics, algorithms, strings, and more
- Open a challenge, read the statement, and edit the starter code
- Run tests, fix failures, then try a related quiz or tutorial lesson
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.