Maybe lists are compared like strings?

I don't understand how this solution works! Is there anyone who can explain it to me?

Yes, you can block methods, but there are a lot of to string methods so you would have to block them all.

It is the same solutions on me...

This is a beginner kata.

To keep it one-lined, I could have written a recursive function to divide by 2 and count the remainders, but was it really necessary ;)?

If that so the author should've written tests for that.

Yeah, String methods weren't allowed!

it's fast! however, according to the description: "...you have to do it without string operation..." lol

Yes, I also thought the same think. This solution absolutely is using string operation.

Should these solution not be failed as they use string methods?

That's cool.. No worries.
The statement is in the description.
"The interesting part of this task is that you have to do it without string operation (hey, it's not really interesting otherwise)"

I did not see the stipulation. Sorry, but the code should work. Just check for syntax errors!

I've tried this. But it did not pass. I thought string operation were not allowed.

Is it even possible to stop people from doing anything?:) It is intended to stimulate self-consciousness and "can I actually dot it?" thoughts, I think.