268. 丢失的数字 (Python 实现)

题目：

示例 1：

示例 2：

示例 3：

示例 4：

代码：

class Solution:
    def missingNumber(self, nums: List[int]) -> int:
        n = len(nums)
        nums = set(nums)
        temp = [x for x in range(0,n+1)]
        temp = set(temp)
        return list(temp.difference(nums))[0]

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