Easy data structure and algorithm practice puzzle.
Given two numbers, return their least common multiple, the smallest number both divide evenly. So 4 and 6 give 12. First find their greatest common divisor with Euclid's algorithm. Then the answer is a x b divided by that gcd. Think of two gears that line up again only every so often.
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 Reading Ledger Balancer, a pipeline you can run and download. See every Software Engineer project.
Browse all 576 puzzles