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16
An Optimal O(log log n) Time Parallel Algorithm for Detecting all Squares in a String
, 1995
"... An optimal O(log log n) time concurrentread concurrentwrite parallel algorithm for detecting all squares in a string is presented. A tight lower bound shows that over general alphabets this is the fastest possible optimal algorithm. When p processors are available the bounds become \Theta(d n ..."
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Cited by 11 (6 self)
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An optimal O(log log n) time concurrentread concurrentwrite parallel algorithm for detecting all squares in a string is presented. A tight lower bound shows that over general alphabets this is the fastest possible optimal algorithm. When p processors are available the bounds become \Theta(d n log n p e + log log d1+p=ne 2p). The algorithm uses an optimal parallel stringmatching algorithm together with periodicity properties to locate the squares within the input string.
WindowAccumulated Subsequence matching Problem is linear
 In Proceedings of the Eighteenth ACM SIGMODSIGACT SIGART Symposium on Principles of Database Systems: PODS 1999, ACM
, 1999
"... Given two strings, text t of length n, and pattern p = p1 : : : pk of length k, and given a natural number w, the subsequence matching problem consists in finding the number of size w windows of text t which contain pattern p as a subsequence, i.e. the letters p1 ; : : : ; pk occur in the window, i ..."
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Cited by 8 (0 self)
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Given two strings, text t of length n, and pattern p = p1 : : : pk of length k, and given a natural number w, the subsequence matching problem consists in finding the number of size w windows of text t which contain pattern p as a subsequence, i.e. the letters p1 ; : : : ; pk occur in the window, in the same order as in p, but not necessarily consecutively (they may be interleaved with other letters). Subsequence matching is used for finding frequent patterns and association rules in databases. We generalize the KnuthMorrisPratt (KMP) pattern matching algorithm; we define a nonconventional kind of RAM, the MPRAMs which model more closely the microprocessor operations; we design an O(n) online algorithm for solving the subsequence matching problem on MPRAMs. Keywords: Subsequence matching, algorithms, frequent patterns, episode matching, datamining. 1 Introduction We address the following problem. Given a text t of length n and a pattern p = p 1 \Delta \Delta \Delta p k of l...
The derivation of online algorithms, with an application to finding palindromes
 Algorithmica
, 1994
"... Abstract. A theory for the derivation of online algorithms is presented. The algorithms are derived in the BirdMeertens calculus for program transformations. This calculus provides a concise functional notation for algorithms, and a few powerful theorems for proving equalities of functions. The th ..."
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Cited by 7 (4 self)
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Abstract. A theory for the derivation of online algorithms is presented. The algorithms are derived in the BirdMeertens calculus for program transformations. This calculus provides a concise functional notation for algorithms, and a few powerful theorems for proving equalities of functions. The theory for the derivation of online algorithms is illustrated with the derivation of an algorithm for finding palindromes. An online lineartime random access machine (RAM) algorithm for finding the longest palindromic substring in a string is derived, For the purpose of finding the longest palindromic substring, all maximal palindromic substrings are computed. The list of maximal palindromes obtained in the computation of the longest palindrome can be used for other purposes such as finding the largest palindromic rectangle in a matrix and finding the shortest partition of a string into palindromes. Key Words. Derivation of online algorithms, Transformational programming, BirdMeertens calcu
Pattern Matching in Strings
 Algorithms and Theory of Computation Handbook, chapter 11
, 1998
"... This paper also proves that this is optimal among algorithms processing the text with a onesymbol buffer. The bound becomes ..."
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Cited by 3 (0 self)
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This paper also proves that this is optimal among algorithms processing the text with a onesymbol buffer. The bound becomes
Online Approximate Matching with Nonlocal Distances
"... Abstract. A black box method was recently given that solves the problem of online approximate matching for a class of problems whose distance functions can be classified as being local. A distance function is said to be local if for a pattern P of length m and any substring T [i, i+m−1] of a text T, ..."
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Cited by 1 (1 self)
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Abstract. A black box method was recently given that solves the problem of online approximate matching for a class of problems whose distance functions can be classified as being local. A distance function is said to be local if for a pattern P of length m and any substring T [i, i+m−1] of a text T, the distance between P and T [i, i + m − 1] is equal to Σj∆(P [j], T [i + j − 1]), where ∆ is any distance function between individual characters. We extend this line of work by showing how to tackle online approximate matching when the distance function is nonlocal. We give solutions which are applicable to a wide variety of matching problems including function and parameterised matching, swap matching, swapmismatch, kdifference, kdifference with transpositions, overlap matching, edit distance/LCS, flipped bit, faulty bit and L1 and L2 rearrangement distances. The resulting unamortised online algorithms bound the worst case running time per input character to within a log factor of their comparable offline counterpart. 1
RealTime String Matching in Sublinear Space
 In CPM
, 2004
"... We study a problem of efficient utilisation of extra memory space in realtime string matching. We propose, for any constant " > 0, a realtime string matching algorithm claiming O(m ) extra space, where m is the size of a pattern. ..."
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We study a problem of efficient utilisation of extra memory space in realtime string matching. We propose, for any constant " > 0, a realtime string matching algorithm claiming O(m ) extra space, where m is the size of a pattern.
Detecting all Squares in a String ∗
"... is permitted for educational or research use on condition that this copyright notice is included in any copy. See back inner page for a list of recent publications in the BRICS Report Series. Copies may be obtained by contacting: BRICS ..."
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is permitted for educational or research use on condition that this copyright notice is included in any copy. See back inner page for a list of recent publications in the BRICS Report Series. Copies may be obtained by contacting: BRICS