Missing Number
Difficulty: Easy
Category: DSA
Topics: Array, Hash Table, Math, Binary Search, Bit Manipulation, Sorting
Asked at: Capital One, Amazon, Facebook, Apple, Microsoft, Oracle, Goldman Sachs, Cisco, Arista Networks
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
**Explanation:**
`n = 3` since there are 3 numbers, so all numbers are in the range `[0,3]`. 2 is the missing number in the range 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 in the range 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 in the range since it does not appear in `nums`.
**Constraints:**
- `n == nums.length`
- `1 <= n <= 104`
- `0 <= nums[i] <= n`
- All the numbers of `nums` are **unique**.
**Follow up:** Could you implement a solution using only `O(1)` extra space complexity and `O(n)` runtime complexity?