Consecutive available seats
Given a list of seat statuses, return the length of the longest consecutive run of available (0) seats.
Power set size
Compute the size of the power set of a given sequence.
Count divisors
Compute the number of positive divisors of a given integer using its prime factorization.
Count Set Bits
Implement a function that returns the number of set bits (1s) in the binary representation of a non-negative integer.
Brian Kernighan count
Implement a function that counts set bits using Brian Kernighan's efficient algorithm.
Find Duplicate Bits
Given a positive integer, return the positions where the bit value appears more than once in its binary form.
Climbing Stairs
Implement a function that returns the number of distinct ways to climb n stairs using steps of 1 or 2.
Unique Paths in a Grid
Count the number of unique paths from the top-left corner to the bottom-right corner of a grid, moving only right and down.
Tiling dominoes count
Given a 2 x n board, count the distinct tilings using 2 x 1 dominoes.
Lemonade Change
Simulate a lemonade stand and decide if you can provide change for each customer using only $5, $10, and $20 bills.
Showing 25–34 of 34 challenges · easy
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.