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Balanced Families of Perfect Hash Functions and Their Applications [PDF]
, 2007 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 ...
Alon, Noga, Gutner, Shai
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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
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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
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A Linear Time Algorithm for Finding Minimal Perfect Hash Functions [PDF]
The Computer Journal, 1993 Summary: A new algorithm for finding minimal perfect hash functions (MPHF) is proposed. The algorithm given three pseudorandom functions \(h_ 0\), \(h_ 1\) and \(h_ 2\), searches for a function \(g\) such that \(F(w)=(h_ 0(w)+g(h_ 1(w))+g(h_ 2(w))) \bmod m\) is a MPHF, where \(m\) is a number of input words.
Zbigniew J. Czech
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Practical minimal perfect hash functions for large databases [PDF]
Communications of the ACM, 1992 We describe the first practical algorithms for finding minimal perfect hash functions that have been used to access very large databases (i.e., having over 1 million keys). This method extends earlier work wherein an 0(n-cubed) algorithm was devised, building upon prior work by Sager that described an 0(n-to the fourth) algorithm.
Edward A. Fox +3 more
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Perfect hashing functions [PDF]
Communications of the ACM, 1977 A refinement of hashing which allows retrieval of an item in a static table with a single probe is considered. Given a set I of identifiers, two methods are presented for building, in a mechanical way, perfect hashing functions, i.e. functions transforming the elements of I into unique addresses.
Renzo Sprugnoli
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Partially perfect hash functions for intersecting families
, 2018 Consider a large network with unknown number of nodes. Some of these nodes coordinate to perform tasks. The number of such coordination groups is also unknown. The only information about the network available is that any two coordinating groups share at least $t$ nodes.
Tapas Kumar Mishra
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Order-preserving minimal perfect hash functions and information retrieval [PDF]
ACM Transactions on Information Systems, 1991 Rapid access to information is essential for a wide variety of retrieval systems and applications. Hashing has long been used when the fastest possible direct search is desired, but is generally not appropriate when sequential or range searches are also required.
Edward A. Fox +3 more
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Constructing Minimal Perfect Hash Functions Using SAT Technology
Proceedings of the AAAI Conference on Artificial Intelligence, 2020 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 perspective of storage efficiency. The information-theoretic limit for MPHFs is 1/ln 2 ≈ 1.44 bits per key.
Sean Weaver, Marijn J. H. Heule
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Engineering Minimal k-Perfect Hash Functions
arXiv.orgESA version with additional ...
Hermann, Stefan +4 more
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