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PHORMA: Perfectly Hashed Order Restricted Multidimensional Array

Lauro Lins·Sostenes Lins·Silvio Melo
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Abstract

In this paper we propose a simple and efficient strategy to obtain a data structure generator to accomplish a perfect hash of quite general order restricted multidimensional arrays named {\em phormas}. The constructor of such objects gets two parameters as input: an n-vector a of non negative integers and a boolean function B on the types of order restrictions on the coordinates of the valid n-vectors bounded by a. At compiler time, the phorma constructor builds, from the pair a,B, a digraph G(a,B) with a single source s and a single sink t such that the st-paths are in 1-1 correspondence with the members of the B-restricted a-bounded array A(a,B). Besides perfectly hashing A(a,B), G(a,B) is an instance of an NW-family. This permits other useful computational tasks on it.

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Lauro Lins, Sostenes Lins, Silvio Melo. 2003-01-24. PHORMA: Perfectly Hashed Order Restricted Multidimensional Array. https://arxiv.org/abs/cs/0301025

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