Some limit results for longest common subsequences
نویسندگان
چکیده
منابع مشابه
Longest Common Subsequences
The length of a longest common subsequence (LLCS) of two or more strings is a useful measure of their similarity. The LLCS of a pair of strings is related to thèedit distance', or number of mu-tations/errors/editing steps required in passing from one string to the other. In this talk, we explore some of the combinatorial properties of the sub-and super-sequence relations, survey various algorit...
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Given two strings X and Y of N and M characters respectively, the Longest Common Sub-sequence LCS Problem asks for the longest sequence of non-contiguous matches between X and Y. Let LN be the length of a LCS of two random strings of size N. Using extensive Monte Carlo simulations for this problem, we nd a nite size scaling law of the form ELN=N = S + AS=ln N p N + :::, where S and AS are const...
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Given a set of t ≥ k + 2 words of length n over a k-letter alphabet, it is proved that there exists a common subsequence among two of them of length at least nk + cn1−1/(t−k−2), for some c > 0 depending on k and t. This is sharp up to the value of c.
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This note provides very simple, efficient algorithms for computing the number of distinct longest common subsequences of two input strings and for computing the number of LCS embeddings.
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The sequence a1 · · · am is a common subsequence in the set of permutations S = {π1, . . . , πk} on [n] if it is a subsequence of πi(1) · · · πi(n) and πj(1) · · · πj(n) for some distinct πi, πj ∈ S. Recently, Beame and Huynh-Ngoc (2008) showed that when k ≥ 3, every set of k permutations on [n] has a common subsequence of length at least n. We show that, surprisingly, this lower bound is asymp...
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ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 1979
ISSN: 0012-365X
DOI: 10.1016/0012-365x(79)90057-8