# Interview - Victor Vannara

### Find All Numbers Disappeared in an Array

> Given an array of `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`

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

`Output: [1,5,9]`

`Explanation: n = 9, the missing elements in this range are 1, 5, 9.`

`Input: nums = [1,1,2]`

`Output: [3]`

`Explanation: n = 3, the missing element in this range is 3.`

public List<Integer> disappeared(List<Integer> nums) {

}

` Brute force: length of array. produce array within range with Natural interval. length 3 array, 'complete' -> [1, 2, 3]
`Brute force: (loop) go through every item in the input, for x in input try and find in the 'complete array'
`Brute force: if x is found, delete item in 'complete'
` Brute force: nums = [1, 1, 2]
` it finds 1 in 'complete' and removes that, doesn't find second '1' so it has nothing to remove, finds 2 and removes from 'complete'
` brute force: output: [3] 
` with two arrays, going through every item in 'complete' as well as 'nums' array
` going through 'complete' for every single numbers in nums
` O(n^2)

set is constant: O(n)

`(notOptimized: sorted array O(n*log(n) * n^2)

`nums = [4,3,2,7,8,2,3,3,6]
`
`