Given the frequency of each lowercase character f(a), f(b)... f(z) and k. Compute the number of unique strings of length k having sorted characters.
k <= 10^5
Sum(f(i)) <= 10^5
Please provide Hints/Approach to solve this problem.
How to solve this combinatorics problem ?
Given the frequency of each lowercase character f(a), f(b)... f(z) and k. Compute the number of unique strings of length k having sorted characters.
k <= 10^5
Sum(f(i)) <= 10^5
Please provide Hints/Approach to solve this problem.