A QUADRATIC UPPER BOUND ON THE SIZE OF A SYNCHRONIZING WORD IN ONE-CLUSTER AUTOMATA

Autor: Dominique Perrin, Marie-Pierre Béal, Mikhail V. Berlinkov
Přispěvatelé: Laboratoire d'Informatique Gaspard-Monge (LIGM), Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS), Department of Algebra and Discrete Mathematics, Ural State University, Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)
Rok vydání: 2011
Předmět:
Zdroj: International Journal of Foundations of Computer Science
International Journal of Foundations of Computer Science, World Scientific Publishing, 2011, 22 (2), pp.277-288. ⟨10.1142/S0129054111008039⟩
ISSN: 1793-6373
0129-0541
DOI: 10.1142/s0129054111008039
Popis: Černý's conjecture asserts the existence of a synchronizing word of length at most (n - 1)2 for any synchronized n-state deterministic automaton. We prove a quadratic upper bound on the length of a synchronizing word for any synchronized n-state deterministic automaton satisfying the following additional property: there is a letter a such that for any pair of states p, q, one has p·ar = q·as for some integers r, s (for a state p and a word w, we denote by p·w the state reached from p by the path labeled w). As a consequence, we show that for any finite synchronized prefix code with an n-state decoder, there is a synchronizing word of length O(n2). This applies in particular to Huffman codes.
Databáze: OpenAIRE