arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1804.06809cs.DS
收藏

关于有无RLE的阿贝尔最长公因子

On Abelian Longest Common Factor with and without RLE

Szymon Grabowski, Tomasz Kociumaka, Jakub Radoszewski

摘要:

我们认为阿贝尔最长公因子问题在两种情况下:当输入字符串是未压缩的,大小为$n$,当输入字符串是游程编码,其压缩表示的大小最多为$m$。字母表大小由$σ$表示。对于未压缩的问题,我们展示了一个$o(n^2)$ -时间和$\Oh(n)$ -空间算法的情况下,$σ=\Oh(1)$,使一个非平凡的使用制表。对于RLE压缩的问题,我们展示了两个算法:一个工作在$\Oh(m^2σ^2 \log^3 m)$时间和$\Oh(m (σ^2+\log^2 m))$空间,它采用线扫描,和一个工作在$\Oh(m^3)$时间和$\Oh(m)$空间,适用于在一个仔细的方式滑动窗口为基础的方法。后者改进了Sugimoto等人最近开发的先前已知的$\Oh(nm^2)$时间和$\Oh(m^4)$时间算法。(IWOCA 2017)和Grabowski(SPIRE 2017)。

英文摘要:

We consider the Abelian longest common factor problem in two scenarios: when input strings are uncompressed and are of size $n$, and when the input strings are run-length encoded and their compressed representations have size at most $m$. The alphabet size is denoted by $σ$. For the uncompressed problem, we show an $o(n^2)$-time and $\Oh(n)$-space algorithm in the case of $σ=\Oh(1)$, making a non-trivial use of tabulation. For the RLE-compressed problem, we show two algorithms: one working in $\Oh(m^2σ^2 \log^3 m)$ time and $\Oh(m (σ^2+\log^2 m))$ space, which employs line sweep, and one that works in $\Oh(m^3)$ time and $\Oh(m)$ space that applies in a careful way a sliding-window-based approach. The latter improves upon the previously known $\Oh(nm^2)$-time and $\Oh(m^4)$-time algorithms that were recently developed by Sugimoto et al.\ (IWOCA 2017) and Grabowski (SPIRE 2017), respectively.

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。

↑