Fully-online construction of suffix trees and DAWGs for multiple texts

We consider fully-online construction of indexing data structures for multiple texts. Let T = {T1, . . . , TK} be a collection of texts. By fully-online, we mean that a new character can be appended to any text in T at any time. This is a natural generalization of semi-online construction of indexing data structures for multiple texts in which, after a new character is appended to the kth text Tk, then its previous texts T1, . . . , Tk−1 will remain static. Our fully-online scenario arises when we index multi-sensor data. We propose fully-online algorithms which construct the directed acyclic word graph (DAWG) and the generalized suffix tree (GST ) for T in O(N log σ) time and O(N) space, where N and σ denote the total length of texts in T and the alphabet size, respectively.