is there someone help me out about this solution ?

I have a question what will happen if n reaches 1 or 0?

Can it ever reach these cases?

I considered using recursion, but I later ended up with loop.
using recursion a great solution!!!

Nice job with Regex

a clever use of the -1 return, it took me a second to catch up

Clever. Not readable. Would not call this "best practice."

Excellent and elegant solution. I like a lot. Only if I can, just add an if to check that the array meets the condition of the 10 numbers, but it has been one of the answers that I liked the most.

You are simulating pattern matching. Read the #Performance note.

Every operation can be a right fold ( one fold per input list, interwoven if more than one ).

I am stuck with my solutions for some time. It is not performant enough to pass the tests. I have looked everywhere for guidance but Lambda Calculus implementation of this scale is rarely talked about. I tried testing solutions in chunks and what I found is when I don't include zipWith in the solutions, solutions are fast enough(around 5000ms) to get a result back from server and pass all the tests except zipWith, but when I include zipWith it's just Execution Timed Out. I wonder whether drop and tail or head is the problem as I have to use them for zipWith.

aha! I was confused as to why the problem wanted you to return -1, now I can see that it sets you up for this solution...

Just clever!!