Medium data structure and algorithm practice puzzle.
Given n, return true if it's a power of two, like 1, 2, 4, or 8. Anything below 1 isn't. Otherwise keep dividing by 2 while n is even. A power of two ends at exactly 1. Anything else ends at an odd number bigger than 1. There's also a bit trick: n & (n - 1) is 0 only when n has a single 1 bit.
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 Throughput Report, a pipeline you can run and download. See every Software Engineer project.
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