Longest common extensions in sublinear space

Philip Bille, Inge Li Gørtz, Mathias Bæk Tejs Knudsen, Moshe Lewenstein, Hjalte Wedel Vildhøj

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

21 Scopus citations


The longest common extension problem (LCE problem) is to construct a data structure for an input string T of length n that supports LCE(i, j) queries. Such a query returns the length of the longest common prefix of the suffixes starting at positions i and j in T. This classic problem has a well-known solution that uses (n) space and O(1) query time. In this paper we show that for any trade-off parameter 1 ≤ τ ≤ n, the problem can be solved in O(image found) space and O(τ) query time. This significantly improves the previously best known time-space trade-offs, and almost matches the best known time-space product lower bound.

Original languageEnglish
Title of host publicationCombinatorial Pattern Matching - 26th Annual Symposium, CPM 2015, Proceedings
EditorsUgo Vaccaro, Ely Porat, Ferdinando Cicalese
PublisherSpringer Verlag
Number of pages12
ISBN (Print)9783319199283
StatePublished - 2015
Event26th Annual Symposium on Combinatorial Pattern Matching, CPM 2015 - Ischia Island, Italy
Duration: 29 Jun 20151 Jul 2015

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference26th Annual Symposium on Combinatorial Pattern Matching, CPM 2015
CityIschia Island

Bibliographical note

Publisher Copyright:
© Springer International Publishing Switzerland 2015.


Dive into the research topics of 'Longest common extensions in sublinear space'. Together they form a unique fingerprint.

Cite this