Problem Single Number

Problem Description:

Given an array of integers, every element appears twice except for one. Find that single one.

Solution:

public int singleNumber(int[] A) {
        Arrays.sort(A);
        for (int i = 1; i < A.length; i += 2) {
            if (A[i-1] != A[i]) {
                return A[i-1];
            }
        }

        return A[A.length - 1];
    }