136. Single Number（js）

136. Single Number

Given a non-empty 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?

Example 1:

Input: [2,2,1]
Output: 1

Example 2:

Input: [4,1,2,1,2]
Output: 4
题意：找到数组中唯一一个打单的数字
代码如下：

/**
 * @param {number[]} nums
 * @return {number}
 */
var singleNumber = function(nums) {
    var res=0;
    for(var i=0;i<nums.length;i++){
        res^=nums[i]
    }
    return res;
};