leetcode-python-缺失数字

1）获取未缺失数字的列表，逐个对比（很慢！）

class Solution:
    def missingNumber(self, nums: List[int]) -> int:
        reallist = [i for i in range(len(nums)+1)]
        for i in reallist:
            if i not in nums:
                return i

2）求和问题

class Solution:
    def missingNumber(self, nums: List[int]) -> int:
        return sum([i for i in range(len(nums)+1)])-sum(nums)