论文标题

在编辑距离下具有变量的匹配模式

Matching Patterns with Variables Under Edit Distance

论文作者

Gawrychowski, Paweł, Manea, Florin, Siemer, Stefan

论文摘要

图案$α$是一串变量和终端字母。我们说$α$与单词$ w $匹配,仅由终端字母组成,如果可以通过用终端单词替换$α$的变量来获得$ w $。匹配的问题,即确定给定模式是否与给定单词匹配,已大量研究:它通常是NP完整的,但是可以为具有限制性结构的模式类别有效地求解。如果我们对$ w $和任何单词$ u $之间的最小锤击距离感兴趣,而通过终端单词替换$α$的变量(在锤式距离下匹配)获得的任何单词$ u $感兴趣,那么一个人可以设计有效的算法和有效的有条件的降低界限,以适合定期的阶级(在该类别中不允许使用可变性的情况),以及在各种情况下,我们可以将各种各样的模式进行划分,以及我们的阶段,我们可以将各种属性划分为一类。模式的结构,即可以交错的不同变量的发生方式。此外,在锤距离距离下,如果变量发生不止一次,并且可以任意将其发生的变量与其他变量交织在一起,即使这些变量仅发生一次,则匹配的问题是棘手的。在本文中,我们考虑了在编辑距离下变量的匹配模式的问题。我们仍然为常规模式类别获得有效的算法和匹配条件下限,但是在这种情况下,问题已经对一般模式而言已经很难过,由单个变量的重复出现与终端交织在一起。

A pattern $α$ is a string of variables and terminal letters. We say that $α$ matches a word $w$, consisting only of terminal letters, if $w$ can be obtained by replacing the variables of $α$ by terminal words. The matching problem, i.e., deciding whether a given pattern matches a given word, was heavily investigated: it is NP-complete in general, but can be solved efficiently for classes of patterns with restricted structure. If we are interested in what is the minimum Hamming distance between $w$ and any word $u$ obtained by replacing the variables of $α$ by terminal words (so matching under Hamming distance), one can devise efficient algorithms and matching conditional lower bounds for the class of regular patterns (in which no variable occurs twice), as well as for classes of patterns where we allow unbounded repetitions of variables, but restrict the structure of the pattern, i.e., the way the occurrences of different variables can be interleaved. Moreover, under Hamming distance, if a variable occurs more than once and its occurrences can be interleaved arbitrarily with those of other variables, even if each of these occurs just once, the matching problem is intractable. In this paper, we consider the problem of matching patterns with variables under edit distance. We still obtain efficient algorithms and matching conditional lower bounds for the class of regular patterns, but show that the problem becomes, in this case, intractable already for unary patterns, consisting of repeated occurrences of a single variable interleaved with terminals.

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