Two Sum
Return indices (i, j) with i < j such that nums[i] + nums[j] == target.
Maximum subarray (Kadane)
Find the contiguous subarray with the largest sum.
Remove duplicates (sorted)
Return a sorted list with duplicates removed.
Product except self
Return an array where output[i] is the product of all elements except nums[i], without using division.
Find Missing Number 1 to n
Given a list containing n-1 distinct integers from 1 to n, find the missing number without using extra space.
Pad Array Edges
Write a function that pads a list with zeros on both ends.
Sort array by parity
Given a list of integers, return a new list with all evens first and odds last, preserving original relative order.
Linear Interpolation Array
Given an array with some None values, replace them by linear interpolation between the nearest known values.
Showing 8 challenges · Lists & Arrays
Lists & Arrays — Python coding challenges
What you will find here
This page lists lists & arrays challenges — real Python problems you solve in the browser IDE with instant test feedback. Each challenge includes a clear brief, starter code, and automated checks.
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.