Your solution is сoncise and understandable at the same time. Well done.

This kata made me RTFM and learn about classes and dunders in Python :D

it just looks funny to me :)

So what!?

Don't know what're you talking about, kata seems fine for me. I would add "don't use strings" as an additional requirement (That is what people do in similar python katas)

Don't know what you're talking about, kata seems good enough for me. I would add "don't use strings" as they do for similar python katas :)

IMO, casts are a red flag for bad design (that's also why the syntax is so ugly), so if you can get rid of one, that's a good idea. It has no runtime impact, indeed.
I am also not 100% certain about how it works, just that it makes code a little more readable as the functor is defined where it's used, instead of the reader having to look it up.
But there are really minor points.

Thanks for you comment! I used static cast to explicitly show that it will be int. As far as I know it has no impact during runtime, i.e. check performed only during compilation.
As for lambda, I use it in C# a lot, but C++ is a mishmash on its own, so this was again for clarity reasons. Besides I don't have a foggiest idea how lamda works in C++ "under the hood" :)

That static cast to int is not required due to the C++ integer promition rules: every arithmetic operation is converted to at least integer size.
Also, have you considered using a lambda instead of the acumCubes function? Worthwile.
Other than that: my compliments that you are using algorithms as much as possible! That makes this the first solution I've read that's actually easy to read and comprehend.

In the problem description, it says the answer should be truncated as an int, not rounded. The answer should be 104.

105 is the correct answer to this problem. Do the math by hand, the right answer is 104.8695.

Thanks for your post!

Awesome kata! Thanks g964!

It seems comparing my own solution against other's makes the biggest difference for me!
I spend almost equal time to solving AND tracking other solutions!
And had to tackle std::chrono to find out if there are any performance boost at all :D

Hi!
Put character into single quotation marks, like this '*'.
Then compiler will count it as single char.
Double quotation marks, like this "*", means that you have a C-string char* containing 1 symbol.