Easy data structure and algorithm practice puzzle.
Given an array and k, return the kth smallest value. Sort from smallest to largest and take the item at index k - 1. It's the mirror of kth largest. Do both and the off-by-one stops being a guess.
Solve it three ways: snap the jigsaw pieces together, fill in the blanks, or type it from scratch against the tests. This one is free.
Every line of the solution comes with a note explaining why it is there, and a step by step replay shows the code running. At level 3, where you type it yourself, you can ask for an AI mock interview on this problem that ends with a hiring manager's scorecard.
Then grow it into a real project with the Software Engineer button: this puzzle becomes the Multi-Trade Merger, a pipeline you can run and download. See every Software Engineer project.
Browse all 576 puzzles