Medium data structure and algorithm practice puzzle.
Given a sorted array and a target, return the value closest to the target. Binary search toward where the target would be, and at every middle you check, keep it if it's closer than your best so far. If you hit the target exactly, return it. The closest value is always one you passed on the way.
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 Trip Bisector, a pipeline you can run and download. See every Software Engineer project.
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