A Sharper Upper Bound for the Separating Words Problem

Abstract

We show that for any two distinct words $ s_1, s_2 $ over an arbitrary alphabets, there exists a deterministic finite automaton with $ O(\log^2 n) $ states that accepts $ s_1 $ and rejects $ s_2 $. This improves the previous upper bound of $O(n^{1/3}\log^7 n)$