Solution: Count the Number of Good Subsequences
Explore how to solve the problem of counting good subsequences in a string by applying dynamic programming and combinatorial mathematics. Understand the use of factorials, modular inverses, and binomial coefficients to efficiently count subsequences where character frequencies match, improving your ability to tackle similar coding interview challenges.
We'll cover the following...
Statement
Count and return the number of good subsequences in the given string s. You may return the modulo
A subsequence is a sequence formed from another sequence by deleting some or no elements while keeping the order of the remaining elements unchanged.
A good subsequence is a subsequence of a string if it is not empty and the frequency of each character is the same.
Constraints:
s.lengthswill only contain ...