ldu_商正昌的博客

Given a string S and two integers L and M, we consider a substring of S as “recoverable” if and only if (i) It is of length M*L; (ii) It can be constructed by concatenating M “diversified” substrings ...

There is a string S only contain lower case English character.(10≤length(S)≤1,000,000) How many substrings there are that contain at least k(1≤k≤26) distinct characters? Input There are multiple test ...