Thepapersinthisvolumewereselectedforpresentationatthe10thInternational Computing and Combinatorics Conference (COCOON 2004), held on August 17-20, 2004 in Jeju Island, Korea. Previous meetings were held in Xi'an (1995), HongKong(1996), Shanghai(1997), Taipei(1998), Tokyo(1999), Sydney(2000), Guilin (2001), Singapore (2002), and Big Sky (2003). In response to the call for papers, 109 extended abstracts were submitted from 23 countries, of which 46 were accepted. The submitted papers were from Belgium (1), Canada (5), China (6), France (1), Germany (6), Hong Kong (8), India (6), Iran (1), Ireland (1), Israel (4), Italy (2), Japan (17), Korea (23), Mexico (3), New Zealand (1), Poland(1), Russia (1), Singapore (5), Sweden (2), Switzerland (3), Taiwan (2), the UK (1), and the USA (9). Each paper was evaluated by at least three program committee members, with the assistance of referees, as indicated by the referee list found in these proceedings. There were many more acceptable papers than there was space available in the conference schedule, and the program committee's task was extremely di?cult. In addition to selected papers, the conference also included threeinvitedpresentationsbyLarsArge, JeongHanKim, andKokichiSugihara. We thank all program committee members and their referees for their - cellent work, especially given the demanding time constraints; they gave the conference its distinctive character. We thank all who submitted papers for c- sideration: they all contributed to the high quality of the conference. Finally, wethankallthepeoplewhoworkedhardtoputinplacethelogistical arrangements of the conference - our colleagues and our graduate students. It is their hard work that made the conference possible and enjoyable.

The papers in this volume were selected for presentation at the Ninth Annual International Symposium on Algorithms and Computation (ISAAC'98), heldonDecember14-16,1998inTaejon, Korea.P- viousmeetingswereheldinTokyo(1990), Taipei(1991), Nagoya (1992), HongKong(1993), Beijing(1994), Cairns(1995), Osaka (1996), andSingapore(1997). The symposium was jointly sponsored by Korea Advanced - stitute of Science and Technology (KAIST) and Korea Information Science Society (KISS) to commemorate its 25th anniversary in - operationwithMinistryofInformationandCommunication, Korea InformationSocietyDevelopmentInstitute, andKoreaScienceand Engineering Foundation. Inresponsetothecallforpapers,102extendedabstractswere submitted from 21 countries. Each submitted paper was reported on byatleastfourprogramcommitteemembers, withtheassistance ofreferees, asindicatedbytherefereelistfoundintheseproce- ings. There were many more acceptable papers than there was space availableinthesymposiumschedule, andtheprogramcommittee's task was extremely di?cult. The 47 papers selected for presentation hadatotalof105authors, residentasfollows: Japan24, Germany 17, UnitedStateofAmerica15, Taiwan10, HongKongandKorea 6each, Spain5, SwitzerlandandAustralia4each, Austria, Canada, andFrance3each, ItalyandNetherlands2each, andGreece1. We thank all program committee members and their referees fortheirexcellentwork, especiallygiventhedemandingtimec- straints; they gave the symposium its distinctive character. We thank all who submitted papers for consideration: they all contributed to the high quality of the symposium. Finally, wethankallthepeoplewhoworkedhardtoputinplace the logistical arrangements of the symposium - our colleagues and our graduate students. It is their hard work that made the sym- sium possi

This volume contains the proceedings of the 21st Annual International S- posium on Algorithms and Computations (ISAAC 2010), held in Jeju, Korea during December 15-17, 2010. Past editions have been held in Tokyo, Taipei, Nagoya,HongKong,Beijing,Cairns,Osaka,Singapore,Taejon,Chennai,Taipei, Christchurch, Vancouver, Kyoto, Hong Kong, Hainan, Kolkata, Sendai, Gold Coast, and Hawaii over the years 1990-2009. ISAACis anannualinternationalsymposiumthatcoversthe verywide range of topics in algorithms and computation. The main purpose of the symposium is to provide a forum for researchers working in algorithms and the theory of computation where they can exchange ideas in this active research community. In response to the call for papers, ISAAC 2010 received 182 papers. Each submission was reviewed by at least three Program Committee members with the assistance of external referees. Since there were many high-quality papers, the Program Committee's task was extremely di?cult. Through an extensive discussion, the Program Committee accepted 77 of the submissions to be p- sented at the conference. Two special issues, one of Algorithmica and one of the International Journal of Computational Geometry and Applications,were prepared with selected papers from ISAAC 2010. The best paper award was given to "From Holant to #CSP and Back: c DichotomyforHolant Problems"byJin-YiCai,SangxiaHuangandPinyanLu, and the best student paper award to "Satis?ability with Index Dependency" by Hongyu Liang and Jing He. Two eminent invited speakers,David Eppstein from UniversityofCalifornia,Irvine,andMattFranklinfromUniversityofCalifornia, Davis, also contributed to this volume.