Will Arrays.sort() increase time complexity and space time complexity?

Question

There is an array related problem, the requirement is that time complexity is O(n) and space complexity is O(1).

If I use Arrays.sort(arr), and use a

Answer 1

Arrays.sort(int[] a) in recent JDK is implemented with Dual-pivot Quicksort algorithm which has O(n log n) average complexity and is performed in-place (e.g. requires no extra space).