Given an array of integers, every element appears twice except for one. Find that single one.
Note:
Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?
public class Solution { public int singleNumber(int[] A) { // Note: The Solution object is instantiated only once and is reused by each test case. int result = 0; if(A.length == 0) return 0; for(int i = 0;i<A.length;i++){ result ^= A[i]; } return result; } }