Missing Number

Given an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is missing from the array.

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Example 1

Input: nums = [3, 0, 1]
Output: 2
Explanation: n = 3 since there are 3 numbers, so all numbers are in the range [0, 3]. 2 is the missing number since it does not appear in nums.

Example 2

Input: nums = [0, 1]
Output: 2
Explanation: n = 2 since there are 2 numbers, so all numbers are in the range [0, 2]. 2 is the missing number since it does not appear in nums.

Example 3

Input: nums = [9, 6, 4, 2, 3, 5, 7, 0, 1]
Output: 8
Explanation: n = 9 since there are 9 numbers, so all numbers are in the range [0, 9]. 8 is the missing number since it does not appear in nums.

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Constraints

• 1 <= nums.length <= 10^4
• 0 <= nums[i] <= nums.length
• All the numbers of nums are unique.