Thank you..I thought as much

i wrote code similar to the top voted but i read your response and code. yours is indeed superior. well done.

You do know that using the "in" operator has a compexity of O(n) too right? The time complexity of your code is basically the same as OP.

Here you only need your own logic of thinking =) There are many solutions to this kata, the more experience in programming, the more concise the code turns out.