Given an integer n, return all the strobogrammatic numbers that are of length n. You may return the answer in any order.
A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).
Example 1:
Input: n = 2 Output: ["11","69","88","96"]
Example 2:
Input: n = 1 Output: ["0","1","8"]
Constraints:
1 <= n <= 14