English

$O(n \log n)$-time text compression by LZ-style longest first substitution

Data Structures and Algorithms 2018-06-14 v1

Abstract

Mauer et al. [A Lempel-Ziv-style Compression Method for Repetitive Texts, PSC 2017] proposed a hybrid text compression method called LZ-LFS which has both features of Lempel-Ziv 77 factorization and longest first substitution. They showed that LZ-LFS can achieve better compression ratio for repetitive texts, compared to some state-of-the-art compression algorithms. The drawback of Mauer et al.'s method is that their LZ-LFS compression algorithm takes O(n2)O(n^2) time on an input string of length nn. In this paper, we show a faster LZ-LFS compression algorithm that works in O(nlogn)O(n \log n) time. We also propose a simpler version of LZ-LFS that can be computed in O(n)O(n) time.

Keywords

Cite

@article{arxiv.1806.04890,
  title  = {$O(n \log n)$-time text compression by LZ-style longest first substitution},
  author = {Akihiro Nishi and Yuto Nakashima and Shunsuke Inenaga and Hideo Bannai and Masayuki Takeda},
  journal= {arXiv preprint arXiv:1806.04890},
  year   = {2018}
}