An efficient implementation of trie structures

Abstract

A new internal array structure, called a double‐array, implementing a trie structure is presented. The double‐array combines the fast access of a matrix form with the compactness of a list form. The algorithms for retrieval, insertion and deletion are introduced through examples. Although insertion is rather slow, it is still practical, and both the deletion and the retrieval time can be improved from the list form. From the comparison with the list for various large sets of keys, it is shown that the size of the double‐array can be about 17 per cent smaller than that of the list, and that the retrieval speed of the double‐array can be from 3–1 to 5–1 times faster than that of the list.

MIRACLE Progress in Monolingual Information Retrieval at Ad-Hoc CLEF 2007

“…The MIRACLE 1 Information Retrieval toolbox is made of basic components in a classical pipeline architecture: stemming, transformation (transliteration, elimination of diacritics and conversion to lowercase), filtering (elimination of stop and frequent words), proper nouns detection and extracting, and paragraph extracting, among others. Some of these basic components can be used in different combinations and order of application for document indexing and for query processing.…”

“…MIRACLE makes use of its own indexing and retrieval engine, which is based on the trie data structure [1]. Tries have been successfully used by the MIRACLE team for years, as an efficient storage and retrieval of huge lexical resources, combined 1 The MIRACLE team is made up of three university research groups located in Madrid (UPM, UC3M and UAM) along with DAEDALUS, a company founded in 1998 as a spin-off of two of these groups.…”

“…Tries have been successfully used by the MIRACLE team for years, as an efficient storage and retrieval of huge lexical resources, combined 1 The MIRACLE team is made up of three university research groups located in Madrid (UPM, UC3M and UAM) along with DAEDALUS, a company founded in 1998 as a spin-off of two of these groups. DAEDALUS is a leading company in linguistic technologies in Spain and is the coordinator of the MIRACLE team.…”

MIRACLE’s Hybrid Approach to Bilingual and Monolingual Information Retrieval

“…The starting point was a set of basic components: stemming, transformation (transliteration, elimination of diacritics and conversion to lowercase), filtering (elimination of stop and frequent words), generation of n-grams, weighting (giving more importance to titles) and relevance feedback. 1 DAEDALUS clients include leading companies in different sectors: media (EL PAÍS), publishing (Grupo SM), telecommunication (Grupo Telefónica), digital rights management (SGAE), photography (StockPhotos) and the reference institution for the Spanish language, Instituto Cervantes. Its portfolio of solutions includes STILUS® (professional spell, grammar and style checking of texts in Spanish), K-Site® (information retrieval, fuzzy search and knowledge management), LUCAS (universal locator of audiovisual contents, an Internet spider), etc.…”

“…In addition, during the last year our group has been developing an indexing system based on the trie data structure [2]. Tries [1] are successfully used by the MIRACLE team for an efficient storage and retrieval of huge lexical resources, combined with a continuation-based approach to morphological treatment. However, the adaptation of these structures to manage efficiently document indexing and retrieval for commercial applications has been a hard task.…”