Find Missing Number

You are given an array containing n distinct numbers taken from the range 0 to n. This means the array should ideally contain all numbers from 0 to n, but one number is missing. Your task is to find and return that missing number.

Input: An array of n integers where each integer is unique and lies between 0 and n (inclusive) except for one missing number.
Output: Return the missing number.

Example Inputs & Outputs

// Example 1:
Input: [3, 0, 1]
Output: 2

// Example 2:
Input: [0, 1]
Output: 2

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

// Example 4:
Input: [0]
Output: 1

Constraints & Edge Cases

• The array contains exactly n numbers.
• All numbers are unique.
• Numbers are in the range 0 to n.
• Only one number is missing from the sequence.
• The array may be in any order.
• Edge case: missing number could be 0 or n.