The 30th Anniversary Conference on Current Trends in Theory and Practice of Computer Science, SOFSEM 2004, took place during January 24-30, 2004, ' in the Hotel VZ M? e? rin, located about 60 km south of Prague on the right shore of Slapsk'ap? rehrada ("Slapy Dam") in the Czech Republic. Having transformed itself over the years from a local event to a fully internat- nal conference, the contemporary SOFSEM tries to keep the best of its winter school aspects (the high number of invited talks) together with multidiscip- narity trends in computer science - this year illustrated by the selection of the following 4 tracks: - Computer Science Theory (Track Chair: Peter Van Emde Boas) - Database Technologies (Track Chair: Jaroslav Pokorny) ' - Cognitive Technologies (Track Chair: Peter Sin? c' ak) ? - Web Technologies (Track Chair: Julius ' Stuller) Its aim was, as always, to promote cooperation among professionals from a- demia and industry working in various areas of computer science.

ICALP { the International Colloquium on Automata, Languages, and Progr- ming { is a series of annual conferences of the European Association for Th- retical Computer Science (EATCS). ICALP'99 was organized by the Institute of Computer Science of the Academy of Sciences of the Czech Republic in - operation with the Action M Agency. Stimulated by the positive experience from previous meetings, the guiding idea of the ICALP'99 organization was to keep and to enhance the idea of a parallel two{track conference with invited plenary talks. Similarly to the two parts of the journal Theoretical Computer Science, Track A of the meeting is devoted to Algorithms, Automata, Complexity, and Games, and Track B to Logic, Semantics, and Theory of Programming. The Program Committee was structured along these same lines. As a further inno- tion, ICALP'99 was coordinated with the European Symposium on Algorithms (ESA'99) in such a way that both conferences took place in the same location with the former immediately followed by the latter. ICALP'99 was the 26th in the series of ICALP colloquia. Previous colloquia were held in Paris (1972), Saarbruc ] ken (1974), Edinburgh (1976), Turku (1977), Udine (1978), Graz (1979), Amsterdam (1980), Haifa (1981), Aarhus (1982), Barcelona (1983), Antwerp (1984), Nafplion (1985), Rennes (1986), Karlsruhe (1987), Tampere (1988), Stresa (1989), Warwick (1990), Madrid (1991), Vienna (1992), Lund (1993), Jerusalem (1994), Szeged (1995), Paderborn (1996), Bo- gna (1997), and Aalborg (1998). In the year 2000 ICALP will be held in Geneva."

This book constitutes the refereed proceedings of the 39th International Conference on Current Trends in Theory and Practice of Computer Science, SOFSEM 2013, held in Spindleruv Mlyn, Czech Republic, in January 2013. The 37 revised full papers presented in this volume were carefully reviewed and selected from 98 submissions. The book also contains 10 invited talks, 5 of which are in full-paper length. The contributions are organized in topical sections named: foundations of computer science; software and Web engineering; data, information, and knowledge engineering; and social computing and human factors.