Given an array nums containing n integers in the range [0, n] without any duplicates, return the single number in the range that is missing from nums.
Follow-up: Could you implement a solution using only O(1) extra space complexity and O(n) runtime complexity?
Example 1:
Input: nums = [1,2,3]
Output: 0
Explanation: Since there are 3 numbers, the range is [0,3]. The missing number is 0 since it does not appear in nums.
Example 2:
Input: nums = [0,2]
Output: 1
Constraints: