Find all Missing Numbers (easy)

Problem Statement

We are given an unsorted array containing numbers taken from the range 1 to ‘n’. The array can have duplicates, which means some numbers will be missing. Find all those missing numbers.

Example 1:

Input: [2, 3, 1, 8, 2, 3, 5, 1]
Output: 4, 6, 7
Explanation: The array should have all numbers from 1 to 8, due to duplicates 4, 6, and 7 are missing.

Example 2:

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

Example 3:

Input:

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