Longest common prefix
Find the longest common prefix among a list of strings.
Product except self
Return an array where output[i] is the product of all elements except nums[i], without using division.
Running Product of Integers
Given a list of integers, return a new list where each element at index i is the product of all elements from index 0 to i.
Subarray sum equals K
Count the number of contiguous subarrays whose sum equals k.
Count of Range Sum
Count contiguous subarrays whose sum lies in a given inclusive range using an efficient divide-and-conquer algorithm.
Trie Insert and Search
Implement a Trie and a scenario runner that executes insert/search/prefix operations.
Multiline anchor match
Extract lines beginning with a plain-text prefix from multiline strings using Python's re module.
Patching Array
Given a sorted array of positive integers and a target n, find the minimum number of patches to make every number from 1 to n representable as a subset sum.
Best Time to Buy and Sell Stock
Given a list of daily stock prices, determine the maximum profit achievable by buying on one day and selling on a later day.
Split list at index
Return prefix and suffix tuples at index k.
Matrix Block Sum
Given a 2D matrix and a block size, compute the sum of each block centered at every cell.
Prefix sum vector
Return running totals for each prefix of the vector.
Showing 1–12 of 12 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.