You are given a range L to R. You are required to find the number of k-special numbers in this range (inclusive). A k-special number is a number that has exactly k unique digits.
For example:
Constraints
1≤T≤101≤L, R≤10181≤k≤7
The 2-special numbers in the range 1 - 12 are 10, 12. Hence the count of 2-special numbers are 2.