Minimal Discriminating Words Problem Revisited

Gawrychowski, Paweł; Kucherov, Grégory; Nekrich, Yakov; Starikovskaya, Tatiana

doi:10.1007/978-3-319-02432-5_17

Cited by 4 publications

(2 citation statements)

References 7 publications

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“…The query processing time is optimal O (p + output) for reporting all maximal generic words, and is near-optimal O (p + log log n + output) for reporting all minimal discriminating words, where output is the size of the output. Later on Gawrychowski et al [6] gave O (n) words space with optimal query time index for minimal discriminating words problem. In this paper, we describe succinct indexes of n log σ + o(n log σ ) + O (n) bits space with O (p + log log n + output) query times for both these problems.…”

Section: Definitionmentioning

confidence: 99%

Succinct indexes for reporting discriminating and generic words

Biswas

Patil

Shah

et al. 2015

Theoretical Computer Science

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We consider the problem of indexing a collection D of D strings (documents) of total n characters from an alphabet set of size σ , such that whenever a pattern P (of p characters) and an integer τ ∈ [1, D] come as a query, we can efficiently report all (i) maximal generic words and (ii) minimal discriminating words as defined below:• maximal generic word is a maximal extension of P occurring in at least τ documents.• minimal discriminating word is a minimal extension of P occurring in at most τ documents. These problems were introduced by Kucherov et al. (SPIRE) [8], they proposed indexes occupying O (n log n) bits with query times O (p + output) and O (p + log log n + output) for Problem (i) and Problem (ii) respectively. The query time for Problem (ii) is later improved to optimal O (p + output) by Gawrychowski et al. (SPIRE) [6]. In this paper, we describe succinct indexes of n log σ + o(n log σ ) + O (n) bits space with near-optimal query times i.e., O (p + log log n + output) for both these problems. Published by Elsevier B.V.

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Section: Definitionmentioning

confidence: 99%

Succinct indexes for reporting discriminating and generic words

Biswas

Patil

Shah

et al. 2015

Theoretical Computer Science

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“…Here we study this problem from the stringology perspective (see e.g. [14,8]). Assume we are given a set of D documents of total length n over an alphabet of size σ, organized in a tree of height h. The tree has D leaves, each associated with a distinct document, and the leaves are all at level h of the tree.…”

Section: Introductionmentioning

confidence: 99%

Efficient tree-structured categorical retrieval

Belazzougui,

Kucherov

2020

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We study a document retrieval problem in the new framework where D text documents are organized in a category tree with a predefined number h of categories. This situation occurs e.g. with taxomonic trees in biology or subject classification systems for scientific literature. Given a string pattern p and a category (level in the category tree), we wish to efficiently retrieve the t categorical units containing this pattern and belonging to the category. We propose several efficient solutions for this problem. One of them uses n(log σ(1+o(1))+ log D + O(h)) + O(∆) bits of space and O(|p| + t) query time, where n is the total length of the documents, σ the size of the alphabet used in the documents and ∆ is the total number of nodes in the category tree. Another solution uses n(log σ(1+o(1))+O(log D))+O(∆)+O(D log n) bits of space and O(|p| + t log D) query time. We finally propose other solutions which are more space-efficient at the expense of a slight increase in query time.

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