Google Online Assessment 2022 (OA) - Maximum Reversed Number
One fragment of a given integer N can be selected and its digits reversed (replaced with a right to left version of themselves). What is the maximum number that can be obtained this way from integer N?
Input
n: an integer 1<=N<=10^9
Output
the greatest integer that can be created by reversing a subset(substring) of its digits
Examples
Example 1:
Input:
n = 5340
Output: 5430
Explanation:
Given N = 5340, the answer is 5430. Fragment "34" can be reversed to "43".
Example 2:
Input:
n = 2043
Output: 4023
Explanation:
Given N = 2043, the answer is 4023. Fragment "204" can be reversed to "402".
Example 3:
Input:
n = 620
Output: 620
Explanation:
Given N = 620, the answer is 620. There is no need to reverse any fragment.
Constraints
1<=N<=10^9