Simple prob

Problem Statement

There is nothing more beautiful than just an integer number.
You are given an integer n. Write down n in decimal notation with no leading zeroes, and let M be the number of written digits. Perform the following operation exactly k times:
Choose two different 1-based positions, i and j, such that 1 <= i < j <= M. Swap the digits at positions i and j. This swap must not cause the resulting number to have a leading zero, i.e., if the digit at position j is zero, then i must be strictly greater than 1.
Return the maximal possible number you can get at the end of this procedure. If it’s not possible to perform k operations, return -1 instead.
Definition

Class:
TheSwap
Method:
findMax
Parameters:
int, int
Returns:
int
Method signature:
int findMax(int n, int k)
(be sure your method is public)

Constraints
-
n will be between 1 and 1,000,000, inclusive.
-
k will be between 1 and 10, inclusive.
Examples
0)

16375
1
Returns: 76315
The optimal way is to swap 1 and 7.
1)

432
1
Returns: 423
In this case the result is less than the given number.
2)

90
4
Returns: -1
We can’t make even a single operation because it would cause the resulting number to have a leading zero.
3)

5
2
Returns: -1
Here we can’t choose two different positions for an operation.
4)

436659
2
Returns: 966354

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