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Related papers: Computing q-gram Frequencies on Collage Systems

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This paper deals with the two fundamental problems concerning the handling of large n-gram language models: indexing, that is compressing the n-gram strings and associated satellite data without compromising their retrieval speed; and…

Information Retrieval · Computer Science 2022-02-08 Giulio Ermanno Pibiri , Rossano Venturini

A Straight-Line Program (SLP) for a string $T$ is a context-free grammar in Chomsky normal form that derives $T$ only, which can be seen as a compressed form of $T$. Kida et al.\ introduced collage systems [Theor. Comput. Sci., 2003] to…

Data Structures and Algorithms · Computer Science 2026-01-27 Soichiro Migita , Kyotaro Uehata , Tomohiro I

We consider the classical exact multiple string matching problem. Our solution is based on $q$-grams combined with pattern superimposition, bit-parallelism and alphabet size reduction. We discuss the pros and cons of the various…

Data Structures and Algorithms · Computer Science 2021-12-07 Robert Susik , Szymon Grabowski , Kimmo Fredriksson

Given a string $S$ of $n$ integers in $[0,\sigma)$, a range minimum query RMQ$(i, j)$ asks for the index of the smallest integer in $S[i \dots j]$. It is well known that the problem can be solved with a succinct data structure of size $2n +…

Data Structures and Algorithms · Computer Science 2019-05-30 Paweł Gawrychowski , Seungbum Jo , Shay Mozes , Oren Weimann

Gradient-based algorithms, popular strategies to optimization problems, are essential for many modern machine-learning techniques. Theoretically, extreme points of certain cost functions can be found iteratively along the directions of the…

Quantum Physics · Physics 2021-04-07 Keren Li , Pan Gao , Shijie Wei , Jiancun Gao , Guilu Long

An occurrence of a repeated substring $u$ in a string $S$ is called a net occurrence if extending the occurrence to the left or to the right decreases the number of occurrences to 1. The net frequency (NF) of a repeated substring $u$ in a…

Data Structures and Algorithms · Computer Science 2026-01-01 Shunsuke Inenaga

We study the problem of estimating frequency response functions of systems of coupled, classical harmonic oscillators using a quantum computer. The functional form of these response functions can be mapped to a corresponding eigenproblem of…

Quantum Physics · Physics 2025-11-14 Sven Danz , Mario Berta , Stefan Schröder , Pascal Kienast , Frank K. Wilhelm , Alessandro Ciani

We study algorithms for solving three problems on strings. The first one is the Most Frequently String Search Problem. The problem is the following. Assume that we have a sequence of $n$ strings of length $k$. The problem is finding the…

Quantum Physics · Physics 2020-01-08 Kamil Khadiev , Artem Ilikaev

Longest common extension queries (often called longest common prefix queries) constitute a fundamental building block in multiple string algorithms, for example computing runs and approximate pattern matching. We show that a sequence of $q$…

Data Structures and Algorithms · Computer Science 2016-04-08 Paweł Gawrychowski , Tomasz Kociumaka , Wojciech Rytter , Tomasz Waleń

We consider string matching with variable length gaps. Given a string $T$ and a pattern $P$ consisting of strings separated by variable length gaps (arbitrary strings of length in a specified range), the problem is to find all ending…

Data Structures and Algorithms · Computer Science 2011-10-14 Philip Bille , Inge Li Goertz , Hjalte Wedel Vildhøj , David Kofoed Wind

We present algorithms for length-constrained maximum sum segment and maximum density segment problems, in particular, and the problem of finding length-constrained heaviest segments, in general, for a sequence of real numbers. Given a…

Computational Geometry · Computer Science 2015-03-19 Md. Shafiul Alam , Asish Mukhopadhyay

Color (or categorical) range reporting is a variant of the orthogonal range reporting problem in which every point in the input is assigned a \emph{color}. While the answer to an orthogonal point reporting query contains all points in the…

Data Structures and Algorithms · Computer Science 2013-06-24 Yakov Nekrich , Jeffrey Scott Vitter

It is generally believed that the preference ranking method PROMETHEE has a quadratic time complexity. In this paper, however, we present an exact algorithm that computes PROMETHEE's net flow scores in time O(qn log(n)), where q represents…

Data Structures and Algorithms · Computer Science 2016-03-02 Toon Calders , Dimitri Van Assche

For almost 35 years, Sch{\"o}nhage-Strassen's algorithm has been the fastest algorithm known for multiplying integers, with a time complexity O(n $\times$ log n $\times$ log log n) for multiplying n-bit inputs. In 2007, F{\"u}rer proved…

Symbolic Computation · Computer Science 2018-04-18 Svyatoslav Covanov , Emmanuel Thomé

Given strings $P$ and $Q$ the (exact) string matching problem is to find all positions of substrings in $Q$ matching $P$. The classical Knuth-Morris-Pratt algorithm [SIAM J. Comput., 1977] solves the string matching problem in linear time…

Data Structures and Algorithms · Computer Science 2010-09-08 Philip Bille

Statistical query (SQ) algorithms are algorithms that have access to an {\em SQ oracle} for the input distribution $D$ instead of i.i.d.~ samples from $D$. Given a query function $\phi:X \rightarrow [-1,1]$, the oracle returns an estimate…

Machine Learning · Computer Science 2017-04-18 Vitaly Feldman

We present two new algorithms for the computation of the q-integer linear decomposition of a multivariate polynomial. Such a decomposition is essential for the treatment of q-hypergeometric symbolic summation via creative telescoping and…

Symbolic Computation · Computer Science 2021-02-15 Mark Giesbrecht , Hui Huang , George Labahn , Eugene Zima

The number of n-gram features grows exponentially in n, making it computationally demanding to compute the most frequent n-grams even for n as small as 3. Motivated by our production machine learning system built on n-gram features, we ask:…

Data Structures and Algorithms · Computer Science 2025-11-20 Ryan R. Curtin , Fred Lu , Edward Raff , Priyanka Ranade

We present the first $\mathrm{o}(n)$-space polynomial-time algorithm for computing the length of a longest common subsequence. Given two strings of length $n$, the algorithm runs in $\mathrm{O}(n^{3})$ time with $\mathrm{O}\left(\frac{n…

Data Structures and Algorithms · Computer Science 2020-09-21 Masashi Kiyomi , Takashi Horiyama , Yota Otachi

We propose a linear optical quantum computation scheme using time-frequency degree of freedom. In this scheme, a qubit is encoded in single-photon frequency combs, and manipulation of the qubits is performed using time-resolving detectors,…

Quantum Physics · Physics 2023-06-13 Tomohiro Yamazaki , Tomoaki Arizono , Toshiki Kobayashi , Rikizo Ikuta , Takashi Yamamoto