The task is to find the second smallest number with a given sum of digits as S and the number of digits as D.
Example 1:
Input:
S = 9
D = 2
Output:
27
Explanation:
18 is the smallest number possible with sum = 9
and total digits = 2, Whereas the second
smallest is 27.
Example 2:
Input:
S = 16
D = 3
Output:
178
Explanation:
169 is the smallest number possible with sum is
16 and total digits = 3, Whereas the second
smallest is 178.
Your Task:
You don't need to read input or print anything. Your task is to complete the function secondSmallest() which takes the two integers S and D respectively and returns a string which is the second smallest number if possible, else return "-1".
Expected Time Complexity: O(D)
Expected Space Complexity: O(1)
Constraints:
1 ≤ S ≤ 10^{5}
1 ≤ D ≤ 10^{5}

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