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.

Example 1:

Input: nums = [3,0,1]
Output: 2

Example 2:

Input: nums = [0,1]
Output: 2

Example 3:

Input: nums = [9,6,4,2,3,5,7,0,1]
Output: 8

Constraints:

• n == nums.length
• 1 ≤ n ≤ 10⁴
• 0 ≤ nums[i] ≤ n
• All the numbers of nums are unique