Approximating LZ77 in Small Space

Abstract

Given a positive \(\epsilon \leq 1\) and read-only access to a string \(S [1..n]\) whose LZ77 parse consists of $z$ phrases, with high probability we can build an LZ77-like parse of $S$ that consists of $\Oh{z / \epsilon}$ phrases using $\Oh{n^{1 + \epsilon}}$ time, $\Oh{n^{1 + \epsilon} / B}$ I/Os (where $B$ is the size of a disk block) and $\Oh{z / \epsilon}$ space.