This book constitutes the refereed proceedings of the 21st Annual Symposium on Theoretical Aspects of Computer Science, STACS 2004, held in Montpellier, France, in March 2004.
The 54 revised full papers presented together with two invited contributions were carefully reviewed and selected from more than 200 submissions. The papers are organized in topical sections on structural complexity, graph algorithms, quantum computing, satisfiability - constraint satisfaction problems, scheduling, algorithms, networks, automata theory and words, path algorithms, cryptography, logic and formal languages, game theory and complexity, and algorithmic information.