268.md

[268] Missing Number

Description

link

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Solution

• See Code

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Code

O(n)

class Solution:
    def missingNumber(self, nums: List[int]) -> int:
        i = 0
        while i < len(nums):
            if nums[i] < len(nums) and nums[i] != i:
                nums[nums[i]], nums[i] = nums[i], nums[nums[i]]
            else:
                i += 1
        for i in range(len(nums)):
            if i != nums[i]:
                return i
        return len(nums)