Sequence Sentential Decision Diagrams

In this paper, we propose a new data structure sequence sentential decision diagram (SSDD) that represents sets of strings. SSDD is a generalized data structure of Sequence Binary Decision Diagram (SeqBDD), that is a similar data structure to a deterministic finite automaton, but the size can be exponentially smaller than the SeqBDD for the same string set. We also provide algorithms to manipulate sets of strings on SSDD. These algorithms allow operations such as intersection, union, and concatenation to be executed on SSDDs under their compressed representations without expanding. We analyzed the size complexity of SSDD and the time complexity of proposed algorithms.