Search in Rotated Array
Implement an efficient search in a rotated sorted array using modified binary search.
Interpolation Search
Implement interpolation search in Python on a sorted list of integers.
Ternary Search
Implement ternary search to locate the maximum of a discrete unimodal function.
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.
Container With Most Water
Given an array of heights, find the maximum area between two vertical lines that can hold water.
Sort Colors (Dutch National Flag)
Implement the Dutch National Flag algorithm to sort an array of 0, 1, 2 in one pass.
Character Replacement Window
Given a string and a number k, find the length of the longest substring that can be made uniform by replacing at most k characters.
Permutation in String
Determine if any permutation of a shorter string appears as a contiguous substring in a longer string using an efficient sliding window.
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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.