English
Related papers

Related papers: Learned Monotone Minimal Perfect Hashing

200 papers

Given a set S of n keys, a k-perfect hash function (kPHF) is a data structure that maps the keys to the first m integers, where each output integer can be hit by at most k input keys. When m=n/k, the resulting function is called a minimal…

Data Structures and Algorithms · Computer Science 2025-07-03 Stefan Hermann , Sebastian Kirmayer , Hans-Peter Lehmann , Peter Sanders , Stefan Walzer

A minimal perfect hash function (MPHF) maps a set of n keys to unique positions {1, ..., n}. Representing an MPHF requires at least 1.44 bits per key. ShockHash is a technique to construct an MPHF and requires just slightly more space. It…

Data Structures and Algorithms · Computer Science 2025-07-03 Stefan Hermann

The monotone minimal perfect hash function (MMPHF) problem is the following indexing problem. Given a set $S= \{s_1,\ldots,s_n\}$ of $n$ distinct keys from a universe $U$ of size $u$, create a data structure $DS$ that answers the following…

Data Structures and Algorithms · Computer Science 2022-07-26 Sepehr Assadi , Martin Farach-Colton , William Kuszmaul

Minimal perfect hashing is the problem of mapping a static set of $n$ distinct keys into the address space $\{1,\ldots,n\}$ bijectively. It is well-known that $n\log_2(e)$ bits are necessary to specify a minimal perfect hash function (MPHF)…

Data Structures and Algorithms · Computer Science 2023-04-13 Giulio Ermanno Pibiri , Yoshihiro Shibuya , Antoine Limasset

Given a set $K$ of $n$ keys, a minimal perfect hash function (MPHF) is a collision-free bijective map $\mathsf{H_{mphf}}$ from $K$ to $\{0, \dots, n-1\}$. This work presents a (minimal) perfect hash function that first prioritizes query…

Data Structures and Algorithms · Computer Science 2026-02-05 Ragnar Groot Koerkamp

Given a set $S$ of $n$ distinct keys, a function $f$ that bijectively maps the keys of $S$ into the range $\{0,\ldots,n-1\}$ is called a minimal perfect hash function for $S$. Algorithms that find such functions when $n$ is large and retain…

Data Structures and Algorithms · Computer Science 2022-02-08 Giulio Ermanno Pibiri , Roberto Trani

Given a set $S$ of $n$ keys, a perfect hash function for $S$ maps the keys in $S$ to the first $m \geq n$ integers without collisions. It may return an arbitrary result for any key not in $S$ and is called minimal if $m = n$. The most…

Data Structures and Algorithms · Computer Science 2026-02-06 Hans-Peter Lehmann , Thomas Mueller , Rasmus Pagh , Giulio Ermanno Pibiri , Peter Sanders , Sebastiano Vigna , Stefan Walzer

A function $f : U \to \{0,\ldots,n-1\}$ is a minimal perfect hash function for a set $S \subseteq U$ of size $n$, if $f$ bijectively maps $S$ into the first $n$ natural numbers. These functions are important for many practical applications…

Data Structures and Algorithms · Computer Science 2023-08-08 Giulio Ermanno Pibiri , Roberto Trani

A minimal perfect hash function (MPHF) bijectively maps a set S of objects to the first |S| integers. It can be used as a building block in databases and data compression. RecSplit [Esposito et al., ALENEX'20] is currently the most space…

Data Structures and Algorithms · Computer Science 2023-07-06 Dominik Bez , Florian Kurpicz , Hans-Peter Lehmann , Peter Sanders

Minimal perfect hash functions (MPHFs) are used to provide efficient access to values of large dictionaries (sets of key-value pairs). Discovering new algorithms for building MPHFs is an area of active research, especially from the…

Logic in Computer Science · Computer Science 2019-11-25 Sean Weaver , Marijn Heule

A minimal perfect hash function bijectively maps a key set $S$ out of a universe $U$ into the first $|S|$ natural numbers. Minimal perfect hash functions are used, for example, to map irregularly-shaped keys, such as string, in a compact…

Data Structures and Algorithms · Computer Science 2019-12-03 Emmanuel Esposito , Thomas Mueller Graf , Sebastiano Vigna

Minimal perfect hash functions provide space-efficient and collision-free hashing on static sets. Existing algorithms and implementations that build such functions have practical limitations on the number of input elements they can process,…

Data Structures and Algorithms · Computer Science 2018-11-06 Antoine Limasset , Guillaume Rizk , Rayan Chikhi , Pierre Peterlongo

Perfect hash functions can potentially be used to compress data in connection with a variety of data management tasks. Though there has been considerable work on how to construct good perfect hash functions, there is a gap between theory…

Data Structures and Algorithms · Computer Science 2007-05-23 Fabiano C. Botelho , Rasmus Pagh , Nivio Ziviani

A minimal perfect hash function (MPHF) maps a set S of n keys to the first n integers without collisions. There is a lower bound of n*log(e)=1.44n bits needed to represent an MPHF. This can be reached by a brute-force algorithm that tries…

Data Structures and Algorithms · Computer Science 2024-06-14 Hans-Peter Lehmann , Peter Sanders , Stefan Walzer

A minimal perfect hash function (MPHF) maps a set of n keys to {1, ..., n} without collisions. Such functions find widespread application e.g. in bioinformatics and databases. In this paper we revisit PTHash - a construction technique…

Data Structures and Algorithms · Computer Science 2024-04-30 Stefan Hermann , Hans-Peter Lehmann , Giulio Ermanno Pibiri , Peter Sanders , Stefan Walzer

A minimal perfect hash function (MPHF) maps a set $S$ of $n$ keys to the first $n$ integers without collisions. There is a lower bound of $n\log_2e-O(\log n)$ bits of space needed to represent an MPHF. A matching upper bound is obtained…

Data Structures and Algorithms · Computer Science 2023-11-14 Hans-Peter Lehmann , Peter Sanders , Stefan Walzer

Consistent hashing is used in distributed systems and networking applications to spread data evenly and efficiently across a cluster of nodes. In this paper, we present MementoHash, a novel consistent hashing algorithm that eliminates known…

Distributed, Parallel, and Cluster Computing · Computer Science 2024-02-28 Massimo Coluzzi , Amos Brocco , Alessandro Antonucci , Tiziano Leidi

A Perfect Hash Function (PHF) is a hash function that has no collisions on a given input set. PHFs can be used for space efficient storage of data in an array, or for determining a compact representative of each object in the set. In this…

Data Structures and Algorithms · Computer Science 2022-11-09 Hans-Peter Lehmann , Peter Sanders , Stefan Walzer

Hashing has recently sparked a great revolution in cross-modal retrieval because of its low storage cost and high query speed. Recent cross-modal hashing methods often learn unified or equal-length hash codes to represent the multi-modal…

Computer Vision and Pattern Recognition · Computer Science 2019-09-13 Xin Liu , Zhikai Hu , Haibin Ling , Yiu-ming Cheung

Similarity searches are a critical task in data mining. As data sets grow larger, exact nearest neighbor searches quickly become unfeasible, leading to the adoption of approximate nearest neighbor (ANN) searches. ANN has been studied for…

Information Retrieval · Computer Science 2025-11-21 Alima Subedi , Sankalpa Pokharel , Satish Puri
‹ Prev 1 2 3 10 Next ›