both fixed

I got it too

Love your solution dagolinuxoid!

+1 don't mutate original array

This is so boring that i can't use object. And why is function in global scope after i use toString() in my object local scope is undefined? I guess problem is because function name _isprivateValue.

Jesus. I doubt just anyone else can compete with you to name at this level. Please name more readily. BTW I guess your solution and mine is equivalent.

白居易 《赋得古原草送别》

离离原上草，一岁一枯荣。
野火烧不尽，春风吹又生。
远芳侵古道，晴翠接荒城。
又送王孙去，萋萋满别情。

You have 2 nested loops there.

And why does that matter? In this case, his algorithm is still O(n).

If there is equality, it's a "touch", not a "collision".

If I log out the input array after the method has run, I get the same as before, i.e. the input is not changed.