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Speeding Up Two StringMatching Algorithms
 ALGORITHMICA
, 1994
"... We show how to speed up two stringmatching algorithms: the BoyerMoore algorithm (BM algorithm), and its version called here the reverse factor algorithm (RF algorithm). The RF algorithm is based on factor graphs for the reverse of the pattern.The main feature of both algorithms is that they scan ..."
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Cited by 94 (17 self)
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We show how to speed up two stringmatching algorithms: the BoyerMoore algorithm (BM algorithm), and its version called here the reverse factor algorithm (RF algorithm). The RF algorithm is based on factor graphs for the reverse of the pattern.The main feature of both algorithms is that they scan the text righttoleft from the supposed right position of the pattern. The BM algorithm goes as far as the scanned segment (factor) is a suffix of the pattern. The RF algorithm scans while the segment is a factor of the pattern. Both algorithms make a shift of the pattern, forget the history, and start again. The RF algorithm usually makes bigger shifts than BM, but is quadratic in the worst case. We show that it is enough to remember the last matched segment (represented by two pointers to the text) to speed up the RF algorithm considerably (to make a linear number of inspections of text symbols, with small coefficient), and to speed up the BM algorithm (to make at most 2.n comparisons). Only a constant additional memory is needed for the search phase. We give alternative versions of an accelerated RF algorithm: the first one is based on combinatorial properties of primitive words, and the other two use the power of suffix trees extensively. The paper demonstrates the techniques to transform algorithms, and also shows interesting new applications of data structures representing all subwords of the pattern in compact form.
Approximate string matching in musical sequences
 In Proceedings of the Prague Stringology Conference
, 2001
"... Abstract. Here we consider computational problems on ffiapproximate and(ffi; fl)approximate string matching. These are two new notions of approximate matching that arise naturally in applications of computer assisted music analysis. We present fast, efficient and practical algorithms for these tw ..."
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Cited by 14 (4 self)
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Abstract. Here we consider computational problems on ffiapproximate and(ffi; fl)approximate string matching. These are two new notions of approximate matching that arise naturally in applications of computer assisted music analysis. We present fast, efficient and practical algorithms for these two notions of approximate string matching.
Approximate String Matching with Gaps
, 2002
"... In this paper we consider several new versions of approximate string matching with gaps. The main characteristic of these new versions is the existence of gaps in the matching of a given pattern in a text. Algorithms are sketched for each version and their time and space complexity is stated. The sp ..."
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Cited by 10 (1 self)
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In this paper we consider several new versions of approximate string matching with gaps. The main characteristic of these new versions is the existence of gaps in the matching of a given pattern in a text. Algorithms are sketched for each version and their time and space complexity is stated. The specific versions of approximate string matching have various applications in computerized music analysis.
A simple fast hybrid patternmatching algorithm
 Proc. 16th Annual Symposium on Combinatorial Pattern Matching, LNCS 3537, SpringerVerlag
, 2005
"... Abstract. The KnuthMorrisPratt (KMP) patternmatching algorithm guarantees both independence from alphabet size and worstcase execution time linear in the pattern length; on the other hand, the BoyerMoore (BM) algorithm provides nearoptimal averagecase and bestcase behaviour, as well as execu ..."
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Cited by 8 (1 self)
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Abstract. The KnuthMorrisPratt (KMP) patternmatching algorithm guarantees both independence from alphabet size and worstcase execution time linear in the pattern length; on the other hand, the BoyerMoore (BM) algorithm provides nearoptimal averagecase and bestcase behaviour, as well as executing very fast in practice. We describe a simple algorithm that employs the main ideas of KMP and BM (with a little help from Sunday) in an effort to combine these desirable features. Experiments indicate that in practice the new algorithm is among the fastest exact patternmatching algorithms discovered to date, perhaps dominant for alphabet size 8 or more. 1
Pattern Matching in Compressed Text and Images
, 2001
"... Normally compressed data needs to be decompressed before it is processed, but if the compression has been done in the fight way, it is often possible to search the data without having to decompress it, or at least only partially decompress it. The problem can be divided into lossless and lossy c ..."
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Cited by 6 (5 self)
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Normally compressed data needs to be decompressed before it is processed, but if the compression has been done in the fight way, it is often possible to search the data without having to decompress it, or at least only partially decompress it. The problem can be divided into lossless and lossy compression methods, and then in each of these cases the pattern matching can be either exact or inexact. Much work has been reported in the literature on techniques for all of these cases, including algorithms that are suitable for pattern matching for various compression methods, and compression methods designed specifically for pattern matching. This work is surveyed in this paper. The paper also exposes the important relationship between pattern matching and compression, and proposes some performance measures for compressed pattern matching algorithms. Ideas and directions for future work are also described.