arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0811.3490cs.DS
收藏

短模式的快速近似串匹配

Faster Approximate String Matching for Short Patterns

Philip Bille

摘要:

研究了经典的近似字符串匹配问题,即给定字符串$P$和$Q$以及一个错误阈值$k$,找出$Q$中与$P$的编辑距离至多为$k$的子串的所有结束位置.令$P$和$Q$分别具有长度$m$和$n$。在一个标准的单位成本字RAM的字大小$w \geq \log n$,我们提出了一种算法,使用时间$$ O(nk \cdot \min(\frac{\log^2 m}{\log n},\frac{\log^2 m\log w}{w}) + n) $$当$P$是短的,即$m = 2^{o(\sqrt{\log n})}$或$m = 2^{o(\sqrt{w/\log w})}$,这提高了以前最好的已知的时间界限的问题。该结果是使用基于制表和字级并行的Landau-Vishkin算法的新型实现的。

英文摘要:

We study the classical approximate string matching problem, that is, given strings $P$ and $Q$ and an error threshold $k$, find all ending positions of substrings of $Q$ whose edit distance to $P$ is at most $k$. Let $P$ and $Q$ have lengths $m$ and $n$, respectively. On a standard unit-cost word RAM with word size $w \geq \log n$ we present an algorithm using time $$ O(nk \cdot \min(\frac{\log^2 m}{\log n},\frac{\log^2 m\log w}{w}) + n) $$ When $P$ is short, namely, $m = 2^{o(\sqrt{\log n})}$ or $m = 2^{o(\sqrt{w/\log w})}$ this improves the previously best known time bounds for the problem. The result is achieved using a novel implementation of the Landau-Vishkin algorithm based on tabulation and word-level parallelism.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑