Your code does not comply to below

Note: if multiple products have the same revenue, order them according to their original positions in the input list.

Because you try to assig int to BigInteger. i variable is int, and Math.Pow(2, i) also returns int.

It depends on the programmer itself. Since the difference of such code neither impacts performance, speed nor efficiency (throughput) (in the current context), it is like asking should I start off with Javascript or Python as my first programming language? ^^

Yes. You want to make sure the password is 4-19 characters long only.

or cast to BigInteger. (BigInteger) Math.Pow() is the same as BigInteger.Pow()

https://learn.microsoft.com/en-us/dotnet/api/system.numerics.biginteger.pow?view=net-7.0

Use BigInteger.Pow instead.

I was wondering about this myself, thanks

I like Number() better, it's clearer and easier to read

yeaa .flat() is only supported in the Node 12.x version which is in the making

Nope see the comments below :)

What version of node is flat available from? What version of Node does kata use?

Please, use Solutions section instead of Discourse to discuss solutions.