Results 11 to 20 of about 647,966 (230)
PHORMA: Perfectly Hashable Order Restricted Multidimensional Arrays [PDF]
arXiv, 2003 In this paper we propose a simple and efficient data structure yielding a perfect hashing of quite general arrays. The data structure is named phorma, which is an acronym for perfectly hashable order restricted multidimensional array. Keywords: Perfect hash function, Digraph, Implicit enumeration, Nijenhuis-Wilf combinatorial family.
Lins, Lauro +2 more
arxiv +5 more sources
Hash and Displace: Efficient Evaluation of Minimal Perfect Hash Functions [PDF]
BRICS Report Series, 1999 A new way of constructing (minimal) perfect hash functions is described. The<br />technique considerably reduces the overhead associated with resolving buckets in two-level hashing schemes. Evaluating a hash function requires just one multiplication and a few additions apart from primitive bit operations.
Rasmus Pagh
openalex +4 more sources
A letter oriented minimal perfect hashing function [PDF]
ACM SIGPLAN Notices, 1982 Cichelli has presented a simple method for constructing minimal perfect hash tables of identifiers for small static word sets. The hash function value for a word is computed as the sum of the length of the word and the values associated with the first and last letters of the word.
Curtis R. Cook, R. R. Oldehoeft
openalex +3 more sources
Balanced Families of Perfect Hash Functions and Their Applications [PDF]
Proc. of 34th ICALP (2007), 435-446, 2008 The construction of perfect hash functions is a well-studied topic. In this paper, this concept is generalized with the following definition. We say that a family of functions from $[n]$ to $[k]$ is a $\delta$-balanced $(n,k)$-family of perfect hash functions if for every $S \subseteq [n]$, $|S|=k$, the number of functions that are 1-1 on $S$ is ...
Noga Alon, Shai Gutner
arxiv +3 more sources
Linear time Constructions of some $d$-Restriction Problems [PDF]
arXiv, 2014 We give new linear time globally explicit constructions for perfect hash families, cover-free families and separating hash functions.
Bshouty, Nader H.
arxiv +4 more sources
Fast and scalable minimal perfect hashing for massive key sets [PDF]
arXiv, 2017 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, due to high construction time, RAM or external memory usage.
Chikhi, Rayan +3 more
arxiv +6 more sources
Quicksort, Largest Bucket, and Min-Wise Hashing with Limited Independence [PDF]
arXiv, 2015 Randomized algorithms and data structures are often analyzed under the assumption of access to a perfect source of randomness. The most fundamental metric used to measure how "random" a hash function or a random number generator is, is its independence: a sequence of random variables is said to be $k$-independent if every variable is uniform and every ...
A. Siegel +7 more
arxiv +4 more sources
An undergraduate project to compute minimal perfect hashing functions [PDF]
ACM SIGCSE Bulletin, 1992 Some heuristics for computing the character weights in a Cichelli-style, minimal perfect hashing function are given. These ideas should perform best when applied to relatively small, static sets of character strings and they can be used as the foundation for a large programming assignment.
John A. Trono
openalex +3 more sources
Minimal perfect hash functions made simple [PDF]
Communications of the ACM, 1980 A method is presented for computing machine independent, minimal perfect hash functions of the form: hash value ← key length + the associated value of the key's first character + the associated value of the key's last character. Such functions allow single probe retrieval from minimally sized tables of identifier lists.
Richard J. Cichelli
openalex +3 more sources
Perfect Hash Function Generation on the GPU with RecSplit [PDF]
, 2022 Minimale perfekte Hashfunktionen (MPHFs) bilden eine statische Menge S von beliebigen Schlüsseln auf die Menge der ersten |S| natürlichen Zahlen bijektiv ab, d. h., jeder Hashwert wird exakt einmal verwendet. Sie sind in vielen Anwendungen hilfreich, zum
Bez, Dominik
core +4 more sources