Displaying similar documents to “Efficient validation and construction of border arrays and validation of string matching automata”

Computing and proving with pivots

Frédéric Meunier (2013)

RAIRO - Operations Research - Recherche Opérationnelle

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A simple idea used in many combinatorial algorithms is the idea of . Originally, it comes from the method proposed by Gauss in the 19th century for solving systems of linear equations. This method had been extended in 1947 by Dantzig for the famous simplex algorithm used for solving linear programs. From since, a pivoting algorithm is a method exploring subsets of a ground set and going from one subset to a new one ′ by deleting an element inside and adding an element outside : ′ =  ...

Computing -Free NFA from Regular Expressions in ( log()) Time

Christian Hagenah, Anca Muscholl (2010)

RAIRO - Theoretical Informatics and Applications

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The standard procedure to transform a regular expression of size to an -free nondeterministic finite automaton yields automata with states and ( ) transitions. For a long time this was supposed to be also the lower bound, but a result by Hromkovic showed how to build an -free NFA with only ( log()) transitions. The current lower bound on the number of transitions is Ω( log()). A rough running time estimation for the common follow sets (CFS) construction proposed...

Analysis of a near-metric TSP approximation algorithm

Sacha Krug (2013)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

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The traveling salesman problem (TSP) is one of the most fundamental optimization problems. We consider the -metric traveling salesman problem ( -TSP), , the TSP restricted to graphs satisfying the -triangle inequality ({}) ≤ (({}) + ({})), for some cost function and any three vertices . The well-known path matching Christofides algorithm (PMCA) guarantees an approximation ratio of 3 /2 and is the best known algorithm for the -TSP, for 1 ≤  ≤ 2....

Computing the Rabin Index of a Parity Automaton

Olivier Carton, Ramón Maceiras (2010)

RAIRO - Theoretical Informatics and Applications

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The Rabin index of a rational language of infinite words given by a parity automaton with states is computable in time ( ) where is the cardinality of the alphabet. The number of values used by a parity acceptance condition is always greater than the Rabin index and conversely, the acceptance condition of a parity automaton can always be replaced by an equivalent acceptance condition whose number of used values is exactly the Rabin index. This...

An aperiodicity problem for multiwords

Véronique Bruyère, Olivier Carton, Alexandre Decan, Olivier Gauwin, Jef Wijsen (2012)

RAIRO - Theoretical Informatics and Applications

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Multiwords are words in which a single symbol can be replaced by a nonempty set of symbols. They extend the notion of partial words. A word is in a multiword if it occurs in word that can be obtained by selecting one single symbol among the symbols provided in each position of . Motivated by a problem on incomplete databases, we investigate a variant of the pattern matching problem which is to decide whether a word is certain in a multiword . We study the language CERTAIN() of multiwords...