activity
20212024
collaborators

6 papers

cs.DS2024

NP-Completeness for the Space-Optimality of Double-Array Tries

Hideo Bannai, Keisuke Goto, Shunsuke Kanda +1

Indexing a set of strings for prefix search or membership queries is a fundamental task with many applications such as information retrieval or database systems. A classic abstract…

cs.DS2023

Acceleration of FM-index Queries Through Prefix-free Parsing

Aaron Hong, Marco Oliva, Dominik Köppl +3

FM-indexes are a crucial data structure in DNA alignment, for example, but searching with them usually takes at least one random access per character in the query pattern. Ferragin…

cs.DS2022

Computing NP-hard Repetitiveness Measures via MAX-SAT

Hideo Bannai, Keisuke Goto, Masakazu Ishihata +3

Repetitiveness measures reveal profound characteristics of datasets, and give rise to compressed data structures and algorithms working in compressed space. Alas, the computation o…

cs.DS2021

HOLZ: High-Order Entropy Encoding of Lempel-Ziv Factor Distances

Dominik Köppl, Gonzalo Navarro, Nicola Prezza

We propose a new representation of the offsets of the Lempel-Ziv (LZ) factorization based on the co-lexicographic order of the processed prefixes. The selected offsets tend to appr…

cs.DS2021

FM-Indexing Grammars Induced by Suffix Sorting for Long Patterns

Jin Jie Deng, Wing-Kai Hon, Dominik Köppl +1

The run-length compressed Burrows-Wheeler transform (RLBWT) used in conjunction with the backward search introduced in the FM index is the centerpiece of most compressed indexes wo…

math.CO2021

On Arithmetically Progressed Suffix Arrays and related Burrows-Wheeler Transforms

Jacqueline W. Daykin, Dominik Köppl, David Kübel +1

We characterize those strings whose suffix arrays are based on arithmetic progressions, in particular, arithmetically progressed permutations where all pairs of successive entries…