# Find All Disappeared Numbers in an Array Lab

In this lab, you will be tasked with finding all the disappeared numbers in an array. The array `nums`

will contain `n`

integers where each number, `nums[i]`

, is in the range `[1, n]`

. Your task is to return an array of all the integers within the range `[1, n]`

that do not appear in `nums`

. Use the ESM (ECMAScript Module) import/export for this lab.

## Lab Description

Given an array `nums`

of `n`

integers where `nums[i]`

is in the range `[1, n]`

, return *an array of all the integers in the range* `[1, n]`

*that do not appear in* `nums`

.

**Example 1:**

**Input:** `nums = [4,3,2,7,8,2,3,1]`

**Output:** `[5,6]`

**Example 2:**

**Input:** `nums = [1,1]`

**Output:** `[2]`

**Example 3:**

**Input:** `nums = [2,2,3,4,5,6,7,8]`

**Output:** `[1]`

### Constraints:

`n == nums.length`

`1 <= n <= 105`

`1 <= nums[i] <= n`

**Follow up:** Could you do it without extra space and in `O(n)`

runtime? You may assume the returned list does not count as extra space.

## Challenges

- Implement the
`findDisappearedNumbers`

function that takes in an array`nums`

and returns an array of missing numbers. - The function should not use extra space and should have a runtime of
`O(n)`

.