【Leetcode】136-single-number【Java实现】【位操作】

看到要求的空间、时间复杂度完全没有头绪。

只好看discussion

好巧妙。。完全想不到。。。还是没有经验啊。。。。

异或操作：相同为0，不同为1

stem:

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?

code:

public class Solution {
    /*
    2015-11-5
    http://blog.csdn.net/is_zhoufeng/article/details/8112199
    */
    public int singleNumber(int[] nums) {
        int res=nums[0];
        
        int len=nums.length;
        
        for(int i=1;i