Find the Missing Number

Find the Missing Number

Given an array of size 'n' containing n-1 distinct numbers in the range of 1 to n. Find the missing number.

Write a function that takes an array of integers as an input and returns the missing number.

Example 1:

Input: [1, 2, 4, 5, 6]
Output: 3

Example 2:

Input: [2, 3, 1, 5]
Output: 4

Constraints:

• The array contains distinct integers in the range 1 to n.
• The size of the array is n-1.