Find Minimum in Rotated Sorted Array
Implement a function that finds the minimum element in a rotated sorted array of distinct integers in O(log n) time.
Koko Eating Bananas
Given piles of bananas and hours, find the minimum integer eating speed Koko needs to finish all piles within H hours.
Capacity to Ship Packages
Given package weights and days allowed, compute the smallest ship capacity that can deliver all packages in order within the given days.
Kth Missing Positive
Given a strictly increasing array and an integer k, return the k-th positive integer that is missing from the array.
Single Element in Sorted Array
Given a sorted array where every element appears exactly twice except one which appears once, return the single element.
Find in Mountain Array
Implement a function to search for a target value in a mountain array using binary search.
Maximum Running Time of n Computers
Use binary search to maximize the running time for n computers with batteries.
Magnetic Force Packages
Given basket positions and k balls, find the largest possible minimum distance between any two balls.
Minimum Speed to Arrive on Time
Given commute distances and a time limit, compute the minimum integer speed so you arrive on time.
Binary Search on Answer: Find the Minimal Maximum Subarray Sum
Implement a function that finds the minimal possible maximum subarray sum when splitting an array into at most k contiguous subarrays.
Rotated Array Search II
Implement a function to search for a target in a rotated sorted array with possible duplicates.
Search 2D Matrix
Given a sorted 2D matrix with sorted rows and first element of each row greater than last of previous, find target efficiently.
Book Allocation: Minimize Maximum Pages
Implement a function that returns the minimized maximum pages when allocating a list of books to k students.
Minimum Days to Make Bouquets
Given bloomDay per flower, find the minimum day to make m bouquets each needing k adjacent flowers.
Nth Magical Number
Given three integers n, a, b, return the nth positive integer that is divisible by either a or b.
Find k Closest Elements to Target
Return exactly k elements from a sorted list that are closest to a given target, preserving order.
Minimum Limit of Balls in a Bag
Given an array of bag sizes and a number of allowed splits, find the minimum possible maximum bag size.
Binary Subarray with Sum
Given a binary list and a goal sum, count the number of subarrays that add up to that goal.
01 Matrix Nearest Zero
Given a binary matrix, return a matrix of the same shape where each cell contains the Manhattan distance to the nearest 0.
Search a 2D Matrix II
Implement an efficient search for a target in a matrix where each row and each column is sorted in ascending order.
Number of Islands in a Matrix
Count the number of distinct islands (connected groups of 1s) in a 2D binary matrix.
Shortest Path in Binary Matrix
Compute the shortest path length from top-left to bottom-right in a binary matrix using 8-directional moves.
Count square submatrices with all ones
Count all square submatrices consisting entirely of 1s in a binary matrix.
Showing 25–47 of 47 challenges · medium
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.