540. Single Element in a Sorted Array

https://leetcode.com/problems/single-element-in-a-sorted-array

Python

Reduce

from functools import reduce


class Solution:
    def singleNonDuplicate(self, nums: List[int]) -> int:
        return reduce(lambda a, b: a^b, nums)

Set

• Did not use the advantage of sorted condition

class Solution:
    def singleNonDuplicate(self, nums: List[int]) -> int:
        buffer = set()

        for num in nums:
            if num not in buffer:
                buffer.add(num)
            else:
                buffer.remove(num)

        return buffer.pop(