[LeetCode][JavaScript]Single Number

Single Number

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?

https://leetcode.com/problems/single-number/

 

 

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要求线性复杂度和不能用额外的空间。

异或运算，两个相同的数，异或的结果是0，一直异或最后剩下的就是结果。

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