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

If the arrays have the same size, and there are guaranteed to be no duplicates, sum each of the arrays. If the sum of the values is different, then they contain different integers.

Edit: You can then sum the log of the entries in the arrays. If that is also the same, then you have the same entries in the array.