What will happen in if n is 0?

It is a nearly perfect solution.
You can be a bit concise by using the reduce method instead, because it uses the first value which is identical here.

fun fact(n: Int): Int {
    return (1..n).reduce { acc, i -> acc * i }
}

All feature requests should be made on CW github.

Feature Request: Country-wise leaderboards?

Thanks..

You can use the author's nickname as the search filter. If you need anything better than that, open an issue on CW github.

Yeah i know but it doesn't have features (such as the check mark when you complete a kata) like the kata list

Not in the Kata list, but you can see the katas someone has authored from his/her profile -> Kata -> Authored.

Feature request: Filter kata by author

hi