Computing Longest Previous Factor in linear time and applications

We give two optimal linear-time algorithms for computing the Longest Previous Factor (LPF) array corresponding to a string w. For any position i in w, LPF[i] gives the length of the longest factor of w starting at position i that occurs previously in w. Several properties and applications of LPF are investigated. They include computing the Lempel-Ziv factorization of a string and detecting all repetitions (runs) in a string in linear time independently of the integer alphabet size. Key words: algorithms design, strings, suffix array, longest common prefix, longest previous factor, Lempel

• Type: Journal
• Year: 2008
• Where: IPL
• Authors: Maxime Crochemore, Lucian Ilie
• Keywords: IPL 2008, Longest Factor, Optimal Linear-time Algorithms, String