Easy data structure and algorithm practice puzzle.
A player picks up items[i] in amounts counts[i]. The same item can be picked up more than once, and one bag slot holds up to maxStack of a single item. Return how many slots the inventory needs. Total up each item with a hash map first, then each item takes its total divided by maxStack, rounded up, which is ceiling division. Rounding down would leave the last few items with nowhere to go.
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 Entity Cache Tier, a pipeline you can run and download. See every Software Engineer project.
Browse all 576 puzzles