LongestSubanagramChain

A word A is called an anagram of a word B if it is possible to change the order of letters in A to get the word B. For example, "coder" is an anagram of "decor".

A word A is called a subword of a word B if A can be obtained from B by removing some letters (possibly 0) from the beginning of B, and removing some letters (possibly 0) from the end of B. For example, "coder" is a subword of "decoder".

A word A is called a subanagram of a word B if there is a word C such that C is an anagram of B and A is a subword of C. For example, "coder" is a subanagram of "record" because the word "coderr" is an anagram of "record" and contains "coder" as a subword.

Let words A and B have the same number of characters. We say that word A dominates word B if for all i, the i-th letter of A is equal to the i-th letter of B or comes after it alphabetically. For example, the word "coder" dominates the word "amber", but doesn't dominate the word "after" (because the 3-rd letter of "coder" is "d" which comes alphabetically before "t" - the 3-rd letter of "after").

A sequence of words A0, A1, ..., An-1 of equal length is called a chain if, for all i from 1 to n-1, word A_i dominates word A_i-1.

You are given a String[] B. Return the maximal value of k where there exists a chain A₀, A₁, ..., A_n-1 such that all words in the chain have length k, and for all i, word A_i is a subanagram of word B[i].