This volume contains the 70 contributed papers and abstracts of two invited l- tures presented at the 12th Annual European Symposium on Algorithms (ESA 2004), held in Bergen, Norway, September 14-17, 2004. The papers in each s- tion of the proceedings are arranged alphabetically. The three distinguished - vited speakers were David Eppstein, Michael Fellows and Monika Henzinger. As in the last two years, ESA had two tracks, with separate program c- mittees, which dealt respectively with: - the design and mathematical analysis of algorithms (the "Design and A- lysis" track); - real-world applications, engineering and experimental analysis of algorithms (the "Engineering and Applications" track). Previous ESAs were held at Bad Honnef, Germany (1993); Utrecht, The Netherlands (1994); Corfu, Greece (1995); Barcelona, Spain (1996); Graz, A- tria (1997); Venice, Italy (1998); Prague, Czech Republic (1999); Saarbruc .. ken, ? Germany (2000); Arhus, Denmark (2001); Rome, Italy (2002); and Budapest, Hungary (2003). The predecessor to the Engineering and Applications track of ESA was the annual Workshop on Algorithm Engineering (WAE). Previous WAEs were held in Venice, Italy (1997); Saarbruc .. ken, Germany (1998); London, ? UK (1999); Saarbruc .. ken, Germany (2000); and Arhus, Denmark (2001). The proceedings of the previous ESAs were published as Springer-Verlag's LNCS volumes 726, 855, 979, 1284, 1461, 1643, 1879, 2161, 2461, and 2832. The proceedingsoftheWAEsfrom1999onwardswerepublishedasSpringer-Verlag's LNCS volumes 1668, 1982, and 2141.

This book constitutes revised selected papers from the 17th International Symposium on Algorithms and Experiments for Wireless Sensor Networks, ALGOSENSORS 2021, held in Lisbon, Portugal*, in September 2021. The 10 full papers presented in this volume were carefully reviewed and selected from 28 submissions. ALGOSENSORS is an international symposium dedicated to the algorithmic aspects of wireless networks. *The conference was held virtually due to the COVID-19 pandemic.

This book constitutes the proceedings of the 31st International Workshop on Combinatorial Algorithms which was planned to take place in Bordeaux, France, during June 8-10, 2020. Due to the COVID-19 pandemic the conference changed to a virtual format. The 30 full papers included in this book were carefully reviewed and selected from 62 submissions. They focus on algorithms design for the myriad of combinatorial problems that underlie computer applications in science, engineering and business.