leetcode : Single Number 數組中找出只出現一次的數字

題目描述

 

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) {
       int singleNum=0;
       for(int i=0;i<A.length;i++){
           singleNum=singleNum^A[i];
       }
       return singleNum;
    }
}