Target sum assignments
Given a list of integers and a target, count how many ways to assign + or - to each number so the total equals the target.
Delete and Earn
Given an array of integers, find the maximum points you can earn by repeatedly deleting a number and all its adjacent values.
Split Array Largest Sum
Minimize the largest sum among k contiguous subarrays using dynamic programming.
Find the Town Judge
Given n people and a trust array, return the town judge or -1.
Find center of star graph
Write a function that finds the center node of a star graph from its list of edges in O(1) time.
Partition to k subsets
Determine if an array of positive integers can be partitioned into k subsets of equal sum using backtracking.
Stock Buy Sell Once
Given daily stock prices, compute the maximum profit you can achieve from buying once and selling once later.
Candy Distribution
Compute the minimum total candies needed so that every child gets at least one and children with higher ratings than neighbors get more candies.
Maximum Ice Cream Bars
Given costs of ice cream bars and coins, return the maximum number you can buy.
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.
Painter Partition Problem
Given board lengths and k painters, find the minimum possible maximum total length a painter must paint.
Job Sequencing with Deadlines and Profits
Given jobs with deadlines and profits, choose a subset that maximizes profit while meeting deadline constraints.
Gas Station Circuit
Given gas and cost arrays for a circular route, determine the starting gas station index that allows a full loop, or -1 if none exists.
Jump Game Reachable
Given an array of non-negative integers where each element is the maximum jump length, determine if you can reach the last index.
Non-overlapping Intervals
Given a list of intervals, return the minimum number of intervals to remove to make the rest non-overlapping.
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.
Search Insert Position
Return the index where a target should be inserted into a sorted list to maintain order.
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.
Median of Sorted Array BS
Implement a binary search algorithm to find the median of two sorted arrays efficiently.
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.
Showing 73–96 of 170 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.