On approximation of bookmark assignments

Yuichi Asahiro, Eiji Miyano, Toshihide Murata, Hirotaka Ono

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Consider a rooted directed acyclic graph G = (V, E) with root r, representing a collection V of web pages connected via a set E of hyperlinks. Each node v is associated with the probability that a user wants to access the node v. The access cost is defined as the expected number of steps required to reach a node from the root r. A bookmark is an additional shortcut from r to a node of G, which may reduce the access cost. The bookmark assignment problem is to find a set of bookmarks that achieves the greatest improvement in the access cost. For the problem, the paper presents a polynomial time approximation algorithm with factor (1 -1/e), and shows that there exists no polynomial time approximation algorithm with a better constant factor than (1-1/e) unless NP ⊆ DTIME(NO(log log N)), where N is the size of the inputs.

Original languageEnglish
Title of host publicationMathematical Foundations of Computer Science 2007 - 32nd International Symposium, MFCS 2007, Proceedings
PublisherSpringer Verlag
Number of pages10
ISBN (Print)9783540744559
Publication statusPublished - 2007
Event32nd International Symposium on Mathematical Foundations of Computer Science, MFCS 2007 - Cesky Krumlov, Czech Republic
Duration: Aug 26 2007Aug 31 2007

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume4708 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other32nd International Symposium on Mathematical Foundations of Computer Science, MFCS 2007
Country/TerritoryCzech Republic
CityCesky Krumlov

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • General Computer Science


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