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Translation of binary regular expressions into nondeterministic ε-free automata with O(n log n) transitions

✍ Scribed by Viliam Geffert


Publisher
Elsevier Science
Year
2003
Tongue
English
Weight
281 KB
Volume
66
Category
Article
ISSN
0022-0000

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✦ Synopsis


We show that every regular expression of size n over a fixed alphabet of s symbols can be converted into a nondeterministic e-free finite-state automaton with Oðsn log nÞ transitions (edges). In case of binary regular languages, this improves the previous known conversion from Oðnðlog nÞ 2 Þ transitions to Oðn log nÞ: For the general case with no bound on cardinality of the input alphabet, our conversion yields a better constant factor in the Oðnðlog nÞ 2 Þ term. The number of states is bounded by OðnÞ: