# Problem Definition

## Description

Given an unsorted array of integers `arr` and a number `s`, write a function `findArrayQuadruplet` that finds four numbers (quadruplet) in `arr` that sum up to `s`. Your function should return an array of these numbers in an ascending order. If such a quadruplet doesn’t exist, return an empty array.

Note that there may be more than one quadruplet in `arr` whose sum is `s`. You’re asked to return the first one you encounter (considering the results are sorted).

Explain and code the most efficient solution possible, and analyze its time and space complexities.

**Example:**

```plaintext
input:  arr = [2, 7, 4, 0, 9, 5, 1, 3], s = 20

output: [0, 4, 7, 9] # The ordered quadruplet of (7, 4, 0, 9)
                     # whose sum is 20. Notice that there
                     # are two other quadruplets whose sum is 20:
                     # (7, 9, 1, 3) and (2, 4, 9, 5), but again you’re
                     # asked to return the just one quadruplet (in an
                     # ascending order)
```

**Constraints:**

* [time limit] 5000ms
* [input] array.integer arr
  * 1 ≤ arr.length ≤ 100
* [input] integer s
* [output] array.integer

## Notes