Longest increasing subsequence
Return the length of the longest strictly increasing subsequence.
Split Array Largest Sum
Minimize the largest sum among k contiguous subarrays using dynamic programming.
Median of Sorted Array BS
Implement a binary search algorithm to find the median of two sorted arrays efficiently.
Kth Smallest in Sorted Matrix
Implement kth_smallest(matrix, k) to return the kth smallest element in a row- and column-sorted square matrix.
Showing 1–4 of 4 challenges · hard
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.