This is such a helpful and clear explanation of this solution. Thank you for taking the time to write this out!

Hilarious

How so? Integer multiplication and division by two are internally realized using bit shifts:

x * 2 == x << 1
x // 2 == x >> 1

Which of these is better? (In my own experiments, I found only a negligible speed difference < 1%)

Hi,

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Cheers

Agree with her, to optimize it would be nice to remove it then the performance would be awesome

It's great and optimized but the elements are being removed from the array and what it we have to use the same array later in the program? It's clever but not a best practice. BTW good efforts :)

nice one :)

How did you even come to that conclusion?

This incorrect solution sometimes passes. Fixed tests should be added.

Well, I see lots of rng.nextInt in the test case generator function

So what? I see 100 consecutive true-tests and 100 consecutive false-tests - is this random or not?