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Related papers: On the Optimal Time/Space Tradeoff for Hash Tables

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In the orthogonal range reporting problem, we are to preprocess a set of $n$ points with integer coordinates on a $U \times U$ grid. The goal is to support reporting all $k$ points inside an axis-aligned query rectangle. This is one of the…

Data Structures and Algorithms · Computer Science 2014-11-04 Allan Grønlund , Kasper Green Larsen

Learned indexes leverage machine learning models to accelerate query answering in databases, showing impressive practical performance. However, theoretical understanding of these methods remains incomplete. Existing research suggests that…

Databases · Computer Science 2024-10-23 Luis Croquevielle , Guang Yang , Liang Liang , Ali Hadian , Thomas Heinis

We develop dynamic dictionaries on the word RAM that use asymptotically optimal space, up to constant factors, subject to insertions and deletions, and subject to supporting perfect-hashing queries and/or membership queries, each operation…

Data Structures and Algorithms · Computer Science 2007-05-23 Erik D. Demaine , Friedhelm Meyer auf der Heide , Rasmus Pagh , Mihai Patrascu

Given $m$ documents of total length $n$, we consider the problem of finding a longest string common to at least $d \geq 2$ of the documents. This problem is known as the \emph{longest common substring (LCS) problem} and has a classic $O(n)$…

Data Structures and Algorithms · Computer Science 2014-07-03 Tomasz Kociumaka , Tatiana Starikovskaya , Hjalte Wedel Vildhøj

Kallampally and Tewari showed in 2016 that there can be a trade-off between determinism and time in space-bounded computations. This they did by describing an unambiguous non-deterministic algorithm to solve Directed Graph Reachability that…

Computational Complexity · Computer Science 2025-04-16 Ronak Bhadra , Raghunath Tewari

We present new tradeoffs between space and query-time for exact distance oracles in directed weighted planar graphs. These tradeoffs are almost optimal in the sense that they are within polylogarithmic, sub-polynomial or arbitrarily small…

Data Structures and Algorithms · Computer Science 2018-11-06 Panagiotis Charalampopoulos , Paweł Gawrychowski , Shay Mozes , Oren Weimann

In the classical balls-and-bins paradigm, where $n$ balls are placed independently and uniformly in $n$ bins, typically the number of bins with at least two balls in them is $\Theta(n)$ and the maximum number of balls in a bin is…

Combinatorics · Mathematics 2010-10-22 Noga Alon , Ori Gurel-Gurevich , Eyal Lubetzky

This paper proposes an efficient and novel method to address range search on multidimensional points in $\theta(t)$ time, where $t$ is the number of points reported in $\Re^k$ space. This is accomplished by introducing a new data structure,…

Computational Geometry · Computer Science 2016-07-04 T. Hema , K. S. Easwarakumar

We ask whether there are fundamental limits on storing quantum information reliably in a bounded volume of space. To investigate this question, we study quantum error correcting codes specified by geometrically local commuting constraints…

Quantum Physics · Physics 2015-05-14 Sergey Bravyi , David Poulin , Barbara Terhal

We introduce linear probing hashing schemes that construct a hash table of size $n$, with constant load factor $\alpha$, on which the worst-case unsuccessful search time is asymptotically almost surely $O(\log \log n)$. The schemes employ…

Data Structures and Algorithms · Computer Science 2023-09-20 Ketan Dalal , Luc Devroye , Ebrahim Malalla

We investigate the complexity of sorting in the model of sequential quantum circuits. While it is known that in general a quantum algorithm based on comparisons alone cannot outperform classical sorting algorithms by more than a constant…

Quantum Physics · Physics 2007-05-23 Hartmut Klauck

In the kSUM problem we are given an array of numbers $a_1,a_2,...,a_n$ and we are required to determine if there are $k$ different elements in this array such that their sum is 0. This problem is a parameterized version of the well-studied…

Data Structures and Algorithms · Computer Science 2018-07-11 Isaac Goldstein , Moshe Lewenstein , Ely Porat

This paper proposed a storing approach for trie structures, called coordinate hash trie. The basic idea is using a global hash table with a special hash function to store all edges of a trie. For a trie with $n$ nodes and an alphabet with…

Data Structures and Algorithms · Computer Science 2023-03-28 Yuxuan Dong

Hash table search strategies have remained a pivotal area of inquiry in computer science over the past several decades. A prevailing viewpoint asserts that random probing stands as the optimal method for open-addressing hash tables.…

Data Structures and Algorithms · Computer Science 2025-03-24 Qiantong Wang

The study of hashing is closely related to the analysis of balls and bins. It is well-known that instead of using a single hash function if we randomly hash a ball into two bins and place it in the smaller of the two, then this dramatically…

Data Structures and Algorithms · Computer Science 2007-05-23 Rina Panigrahy

Linear-probing hash tables have been classically believed to support insertions in time $\Theta(x^2)$, where $1 - 1/x$ is the load factor of the hash table. Recent work by Bender, Kuszmaul, and Kuszmaul (FOCS'21), however, has added a new…

Data Structures and Algorithms · Computer Science 2025-01-22 Mark Braverman , William Kuszmaul

Given a specified average load factor, hash tables offer the appeal of constant time lookup operations. However, hash tables could face severe hash collisions because of malicious attacks, buggy applications, or even bursts of incoming…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-06-02 Junchang Wang , Xiong Fu , Fu Xiao , Chen Tian

We show the $O(\log n)$ time extract minimum function of efficient priority queues can be generalized to the extraction of the $k$ smallest elements in $O(k \log(n/k))$ time (we define $\log(x)$ as $\max(\log_2(x), 1)$.), which we prove…

Data Structures and Algorithms · Computer Science 2022-01-11 Bryce Sandlund , Lingyi Zhang

[See the paper for the full abstract.] We show tight upper and lower bounds for time-space trade-offs for the $c$-Approximate Near Neighbor Search problem. For the $d$-dimensional Euclidean space and $n$-point datasets, we develop a data…

Data Structures and Algorithms · Computer Science 2019-10-04 Alexandr Andoni , Thijs Laarhoven , Ilya Razenshteyn , Erik Waingarten

Most hash tables have an insertion time of $O(1)$, possibly qualified as expected and/or amortised. While insertions into cuckoo hash tables indeed seem to take $O(1)$ expected time in practice, only polylogarithmic guarantees are proven in…

Data Structures and Algorithms · Computer Science 2022-04-26 Stefan Walzer