剑指 Offer 56

class Solution(object):
    def singleNumbers(self, nums):
        """
        :type nums: List[int]
        :rtype: List[int]
        """
        nums.sort()
        res = []
        # 特判：处理第一个和最后一个元素
        if nums[0] != nums[1]:
            res.append(nums[0])
        if nums[-1] != nums[-2]:
            res.append(nums[-1])
        for i in range(1, len(nums) - 1):
            if nums[i] == nums[i - 1] or nums[i] == nums[i + 1]:
                continue
            else:
                res.append(nums[i])
        return res


if __name__ == '__main__':
    s = Solution()
    print(s.singleNumbers(nums=[4, 1, 4, 6]))