Easy data structure and algorithm practice puzzle.
Given the cache's keys in order of use, oldest first, and how many it can hold, return the keys that have to go, oldest first. If everything fits, return an empty list. With the order already tracked, eviction is just counting how many are over the limit and taking that many from the front.
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 Priority Desk, a pipeline you can run and download. See every Software Engineer project.
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