题目

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?

中文大意

给定一个整数数组，里面只有一个数只出现一次，其余的数都出现两次，找出只出现一次的数。

解题思路

采用异或运算^
a ^ a = 0
a ^ 0 = a
a ^ b ^ c = a ^ (b ^ c)
因此所有数进行异或，最终得到的就是只出现一次的数

代码

func singleNumber(nums []int) int {
    var ret int
    ret = 0
    for _,v := range nums {
        ret = ret ^ v
    }
    return ret
}