Count Numbers Changed by Valid Digit Rotation

### Problem Rotate every decimal digit individually using these rules:0,1,8 stay unchanged;2 and 5 exchange;6 and 9 exchange;3,4,7 are invalid. Do not reverse digit order. Count integers from 1 through n that remain valid and become a different number. ```cpp class Solution { public: int rotatedDigits(int n); }; ``` ### Examples **Example 1:** ```text n = 5 Output: 2 Explanation: Only2 and5 are valid and changed. ``` **Example 2:** ```text n = 15 Output: 6 Explanation: The qualifying numbers are2,5,6,9,12,15. ``` ### Constraints - The inclusive upper bound n lies in [1,10000]. ### Contract considerations Apply the stated mapping to every digit. ```hint Read the boundary condition Which digits certify a change, and which invalidate the number? ``` ### Boundary reminders Apply the stated mapping to every digit.