given a string s and a list of strings st.

A string is special if its length >= 3 and it is a subsequence of the string s, and the string should be present in st.

given a string s and st, return true if all the subsequences(length >= 3) are special words. else return false.

I have solved this question using bruteforce recursion generating all the subsequences and checking. Can someone share any better approaches for this? And any idea when I would get the rejection letter?