find if two arrays contain the same set of integers without extra space and faster than NlogN

Question

I came across this post, which reports the following interview question:

Given two arrays of numbers, find if each of the two arrays have the same s

Answer 1

For each integer i check that the number of occurrences of i in the two arrays are either both zero or both nonzero, by iterating over the arrays.

Since the number of integers is constant the total runtime is O(n).

No, I wouldn't do this in practice.