Three New Algorithms for Regular Language Enumeration

We present new and more efficient algorithms for regular language enumeration problems. The min-word problem is to find the lexicographically minimal word of length n accepted by a given NFA, the cross-section problem is to list all words of length n accepted by an NFA in lexicographical order, and the enumeration problem is to list the first m words accepted by an NFA according to length-lexicographic order. For the min-word and cross-section problems, we present algorithms with better asymptotic running times than previously known algorithms. Additionally, for each problem, we present algorithms with better practical running times than previously known algorithms.

• Type: Conference
• Year: 2009
• Where: COCOON
• Authors: Margareta Ackerman, Erkki Mäkinen
• Keywords: COCOON 2009, Combinatorics, Cross-section Problems, Enumeration Problem, Language Enumeration Problems