Please don't do that, we are not in 1970's C code. Variables should be declared as local as possible. You are not saving up anything and the compiler will optimize it for you anyways.

Clever approach but the time complexity is O(N^2)

You could declare variable c out of for, that variable will created for one times

how do you test for time?

great solution bro

i agree. it kind of kills the point of this kata

No, time complexity is still O(n * (n + n + n)) = O(n²).

It has to be one or the other, since all the other values are equal to each other.

I run your in 600+ ms and mine in 260 ms.
I test every value until I find the unique where you sort the whole array.

@kjanus-thecreator Description says. "The tests contain some very huge arrays, so think about performance"
I insist this 6 kyu kata's solution should be implemented in imperative style, not two-lines declarative one. Otherwise it must be 7 kyu.