have you been able to solve it?

definetly not lol

Thanks for your help. I posted my solution because no one didn't comment on my first comment.

Please don't post solutions in Discourse. It means you can make changes (if you want) to your code before submitting it. After that, that's the solution it'll show no matter how many times you submit another version. Note this kata is a Draft, so you can't submit your solution.

I have solved it and passes all test but i don't know why I can't sbmit my solution.

does one line of code has effect on time complexity

i don't know where some people get their ideas from. I get jealous when i see some people's code

my code is similar to yours but i use set to remove the duplicates

ok

you are right

it is for readability

Probably forgot to delete it

what does "found" do in your solution