This book constitutes the refereed proceedings of the 9th Scandinavian Workshop on Algorithm Theory, SWAT 2004, held in Humlebaek, Denmark in July 2004. The 40 revised full papers presented together with an invited paper and the abstract of an invited talk were carefully reviewed and selected from 121 submissions. The papers span the entire range of theoretical algorithmics and applications in various fields including graph algorithms, computational geometry, scheduling, approximation algorithms, network algorithms, data storage and manipulation, bioinformatics, combinatorics, sorting, searching, online algorithms, optimization, etc.

This volume contains the papers presented at SWAT 2004, the 9th Scandi- vian Workshop on Algorithm Theory, which was held on July 8-10, 2004, at the Louisiana Museum of Modern Art in Humlebæk on the Øresund coast north of Copenhagen. The SWAT workshop, in reality a full-?edged conference, has been held biennially since 1988 and rotates among the ?ve Nordic countries, D- mark, Finland, Iceland, Norway, and Sweden. The previous meetings took place ? in Halmstad (1988), Bergen (1990), Helsinki (1992), Arhus (1994), Reykjavik (1996), Stockholm (1998), Bergen (2000), and Turku (2002). SWAT alternates with the Workshop on Algorithms and Data Structures (WADS), held in o- numbered years. Thecallforpapersinvitedcontributionsonallaspectsofalgorithmtheory.A totalof121submissionswasreceived--anoverallSWAThigh.Theseunderwent thorough reviewing, and the program committee met in Copenhagen on March 20-21, 2004, and selected 40 papers for presentation at the conference. The programcommitteewasimpressedwiththequalityofthesubmissionsand,given the constraints imposed by the choice of conference venue and duration, had to make some tough decisions. The scienti?c program was enriched by invited presentations by Gerth Stølting Brodal (University of Aarhus) and Charles E. Leiserson (Massachusetts Institute of Technology). TwosatelliteeventswereheldimmediatelybeforeSWAT2004:theWorkshop on On-Line Algorithms (OLA 2004), organized by members of the Department of Mathematics and Computer Science at the University of Southern Denmark, and the Summer School on Experimental Algorithmics, organized by the Perf- mance Engineering Laboratory in the Department of Computing at the Univ- sity of Copenhagen. More information about SWAT 2004 and its satellite events is available at the conference web sitehttp://swat.diku.dk/.

This book constitutes the refereed proceedings of the 9th Scandinavian Workshop on Algorithm Theory, SWAT 2004, held in Humlebaek, Denmark in July 2004. The 40 revised full papers presented together with an invited paper and the abstract of an invited talk were carefully reviewed and selected from 121 submissions. The papers span the entire range of theoretical algorithmics and applications in various fields including graph algorithms, computational geometry, scheduling, approximation algorithms, network algorithms, data storage and manipulation, bioinformatics, combinatorics, sorting, searching, online algorithms, optimization, etc.

This book constitutes the refereed proceedings of the 11th Scandinavian Workshop on Algorithm Theory, SWAT 2008, held in Gothenborg, Sweden, in July 2008. The 36 revised full papers presented together with 2 invited lectures were carefully reviewed and selected from 111 submissions. Papers were solicited for original research on algorithms and data structures in all areas, including but not limited to: approximation algorithms, computational biology, computational geometry, distributed algorithms, external-memory algorithms, graph algorithms, online algorithms, optimization algorithms, parallel algorithms, randomized algorithms, string algorithms and algorithmic game theory.

This book constitutes the refereed proceedings of the 15th International Symposium Fundamentals of Computation Theory, FCT 2005, held in Lübeck, Germany in August 2005. The 46 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 105 submissions. The papers are organized in topical sections on circuits, automata, complexity, approximability, computational and structural complexity, graphs and complexity, computational game theory, visual cryptography and computational geometry, query complexity, distributed systems, automata and formal languages, semantics, approximation algorithms, average case complexity, algorithms, graph algorithms, and pattern matching.

This book constitutes the thoroughly refereed post proceedings of the Second International Workshop on Approximation and Online Algorithms, WAOA 2004, held in Bergen, Norway in September 2004. The 21 revised full papers presented together with 2 invited papers were carefully selected during two rounds of reviewing and improvement from 47 submissions. WAOA is devoted to the design and analysis of algorithms for online and computationally hard problems. Among the topics addressed are applications to game theory, approximation classes, coloring and partitioning, competitive analysis, computational finance, cuts and connectivity, geometric computations, inapproximability results, mechanism design, network design, routing, packing and covering, paradigms, randomization techniques, and scheduling problems.