Faster Compact On-Line Lempel-Ziv Factorization

Medientyp: E-Artikel; Elektronischer Konferenzbericht; Sonstige Veröffentlichung

Titel: Faster Compact On-Line Lempel-Ziv Factorization

Beteiligte: Yamamoto, Jun'ichi [VerfasserIn]; I, Tomohiro [VerfasserIn]; Bannai, Hideo [VerfasserIn]; Inenaga, Shunsuke [VerfasserIn]; Takeda, Masayuki [VerfasserIn]

Erschienen: Schloss Dagstuhl – Leibniz-Zentrum für Informatik, 2014

Sprache: Englisch

DOI: https://doi.org/10.4230/LIPIcs.STACS.2014.675

Schlagwörter: Lempel-Ziv Factorization ; String Index

Entstehung:

Anmerkungen: Diese Datenquelle enthält auch Bestandsnachweise, die nicht zu einem Volltext führen.

Beschreibung: We present a new on-line algorithm for computing the Lempel-Ziv factorization of a string that runs in O(N.log(N)) time and uses only O(N.log(s)) bits of working space, where N is the length of the string and s is the size of the alphabet. This is a notable improvement compared to the performance of previous on-line algorithms using the same order of working space but running in either O(N.log^3(N)) time [Okanohara and Sadakane, 2009] or O(N.log^2(N)) time [Starikovskaya, 2012]. The key to our new algorithm is in the utilization of an elegant but less popular index structure called Directed Acyclic Word Graphs, or DAWGs [Blumer et al., 1985]. We also present an opportunistic variant of our algorithm, which, given the run length encoding of size m of a string of length N, computes the Lempel-Ziv factorization of the string on-line, in O(m.min{log(log(m)).log(log(N))/(log(log(log(N)))), (log(m))^{1/2}/(log(log(m)))^{1/2})}) time and O(m.log(N)) bits of space.

Zugangsstatus: Freier Zugang

Nur in Feld suchen:

Zuletzt gesuchte Begriffe: