Longest Previous Non-overlapping Factors Computation

Abstract

We study the problem of finding the Longest Previous non-overlapping Factor (LPnF) occurring at each position of a string. The notion of LPnF table is a variant of the Longest Previous Factor (LPF) table and is an essential element for the design of efficient algorithms on strings. The LPnF table is related to Ziv-Lempel factorization which is used for text compression. In this paper, we describe an algorithm for computing the LPnF table of a string from its Suffix Automaton. The algorithm runs in linear time on a fixed size alphabet and applications of this algorithm are for text compression.