x is a good if after rotating each digit individually by 180 degrees, we get a valid number that is different from
x. Each digit must be rotated - we cannot choose to leave it alone.
A number is valid if each digit remains a digit after rotation. For example:
8rotate to themselves,
5rotate to each other (in this case they are rotated in a different direction, in other words,
9rotate to each other, and
Given an integer
n, return the number of good integers in the range
Input: n = 10 Output: 4 Explanation: There are four good numbers in the range [1, 10] : 2, 5, 6, 9. Note that 1 and 10 are not good numbers, since they remain unchanged after rotating.
Input: n = 1 Output: 0
Input: n = 2 Output: 1
1 <= n <= 104