136. single-number

description:

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

code:

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

result:

personal opinion:

来源：CSDN

作者：sky527759

链接：https://blog.csdn.net/sky527759/article/details/103743027