Instead of saying - 1 * (expression), you could say - (expression), as boolean values are interpreted as 1 or 0 in arithmetic, and you can subtract those as well like you can do with (almost) any value.

i dont see an 'X-Ray' anywhere in the Python code

In python the preloaded X-ray is wrong. R should be r to match the testcases.

Is regex more faster solution than using for loop?

Hi,

Unfortunately, you did a duplicate of this one: https://www.codewars.com/kata/5b5736abf1d553f844000050
The context isn't exactly the same, but the underlying logic is exactly the same, your kata only adds iterating over the board first, and converting to a boolean for the output.
Other than that, a well done kata, yes. Note that mixing ints and strings in the input isn't a good idea. You could have used characters for the tiles as well.

Cheers

Very well written kata, keep 'em coming!
I would consider changing the letter for knight to N as K usually represents the King in chess.

Pretty interesting Kata.
Am I the only one that thinks that this actually is a bit harder then 6 KYU in general?
Atleast from c++ pov I'd rate it 5

Very good kata, thanks for spending your time creating these!

Thanks for a very fun kata!
I know this game as Othello, not Reversi ;)

If it is faster, why not just give it a shot?

If he waits until 0.9, he misses the 1.0->1.2 and 0.8->0.9 ride up and only makes 1.11x from 0.9->1.0. It's a smaller profit than a possible 1.5x, so not ideal

Why in the example on step 1 is the ideal trader not buying at 0.9 instead of 1.0?

Very fun kata, however, I think its easier than 2 kyu

Jeez this was my first attempt att a 1 KYU kata. It was frustrating, time consuming, moments of happiness followed by even more frustration but finally, insane amounts of satisfaction.
Thanks Voile for a great kata, I learned alot about myself, and some modular arithmetics.