Fast online Lempel-Ziv factorization in compressed space


Let T be a text of length n on an alphabet Σ of size σ, and let H0 be the zero-order empirical entropy of T. We show that the LZ77 factorization of T can be computed in nH0+o(nlogσ)+O(σlogn) bits of working space with an online algorithm running in O(nlogn) time. Previous space-efficient online solutions either work in compact space and O(nlogn) time, or in succinct space and O(nlog3n) time.

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)