Algorithms for finding patterns in strings
Handbook of theoretical computer science (vol. A)
A Four Russians algorithm for regular expression pattern matching
Journal of the ACM (JACM)
From regular expressions to DFA's using compressed NFA's
Theoretical Computer Science
Journal of the ACM (JACM)
Introduction To Automata Theory, Languages, And Computation
Introduction To Automata Theory, Languages, And Computation
On the Power of Communication in Alternating Machines
MFCS '88 Proceedings of the Mathematical Foundations of Computer Science 1988
On the Power of Synchronization in Parallel Computations
MFCS '89 Proceedings on Mathematical Foundations of Computer Science 1989
An Improved Algorithm for the Membership Problem for Extended Regular Expressions
MFCS '02 Proceedings of the 27th International Symposium on Mathematical Foundations of Computer Science
The Membership Problem for Regular Expressions with Intersection Is Complete in LOGCFL
STACS '02 Proceedings of the 19th Annual Symposium on Theoretical Aspects of Computer Science
Fast Algorithms for Extended Regular Expression Matching and Searching
STACS '03 Proceedings of the 20th Annual Symposium on Theoretical Aspects of Computer Science
A New Recognition Algorithm for Extended Regular Expressions
ISAAC '01 Proceedings of the 12th International Symposium on Algorithms and Computation
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This paper is concerned with the recognition problem for semi-extended regular expressions: given a semi-extended regular expression r of length m and an input string x of length n, determine if x ∈ L(r), where L(r) denotes the language denoted by r. Although the recognition algorithm based on nondeterministic finite automata (NFAs) for regular expressions is widely known, a similar algorithm based on finite automata is currently not known for semi-extended regular expressions. The existing algorithm is based on dynamic programming. We here present an efficient automata-based recognition algorithm by introducing a new model of alternating finite automata called partially input-synchronized alternating finite automata (PISAFAs for short). Our algorithm based on PISAFAs runs in O(mn2) time and O(mn + kn2) space, though the existing algorithm based on dynamic programming runs in O(mn3) time and O(mn2) space, where k is the number of intersection operators occurring in r. Thus our algorithm significantly improves the existing one.