Easy data structure and algorithm practice puzzle.
Given a list of action values, return the index of the best one. If two tie, return the first. Walk the list once and keep the index of the best so far. Always being greedy has a catch: the agent never tries an action it underrates, so it never finds out it was wrong. That's why agents sometimes take a random action on purpose.
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 Step Priority Desk, a pipeline you can run and download. See every Software Engineer project.
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