Suffix tree automata in state space search

Abstract

An on-line learning algorithm for pruning state space search is described in this paper. The algorithm is based on a finite state machine which is both created and used in the search. The pruning technique is necessary when memory resources in searching huge problem spaces are restricted. A duplicate sequence is a generating path in the search tree that has a counterpart with smaller weight. The automaton provides the dictionary operations Insert and Delete for the duplicate sequences found in the search and Search for pruning the search tree.

The underlying data structure is a multi suffix tree. Given that the alphabet Σ of state transitions is bounded by a constant an optimal worst case bound of O(|m|) for both insertion and deletion of a duplicate sequence m ∈ Σ^* is achieved. Using the structure as a finite state machine we can incrementally accept a given sequence x in time O(|x|).