Maximize an Integer with at Most One Digit Swap

### Problem Return the greatest integer obtainable from num by swapping two decimal digit positions at most once. Leaving the digits unchanged is allowed. ```cpp class Solution { public: int maximumSwap(int num); }; ``` ### Examples **Example 1:** ```text num = 1993 Output: 9913 Explanation: Swap the first 1 with the rightmost 9. ``` **Example 2:** ```text num = 4321 Output: 4321 Explanation: No swap improves the value. ``` ### Constraints - The integer num is nonnegative and at most 100000000. ### Clarifying Questions Prioritize the earliest improved digit and allow no swap when already maximal. ```hint Read the boundary condition If the largest useful replacement digit appears twice, which occurrence should receive the smaller digit? ``` ### Contract considerations Prioritize the earliest improved digit and allow no swap when already maximal.