[LeetCode]136. Single Number

Given an array of integers, every element appears twice except for one. Find that single one.

找出一个数组中唯一一个只出现了一次的数，其余的都出现了两次

class Solution(object):
    def singleNumber(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if len(nums)==1:
            return nums[0]
        num = 0
        for i in nums:
            num ^= i
        return num