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International Colloquium on Automata, Languages, and Programming

ICALP 1998: Automata, Languages and Programming pp 79–90Cite as

Simpler and faster dictionaries on the AC0 RAM

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Part of the book series: Lecture Notes in Computer Science ((LNCS,volume 1443))

Abstract

We consider the static dictionary problem of using O(n) w-bit words to store n w- bit keys for fast retrieval on a w-bit AC0 RAM, i.e., on a RAM with a word length of w bits whose instruction set is arbitrary, except that each instruction must be realizable through an unbounded-fanin circuit of constant depth and wO(1) size. We improve the best known upper bound for moderate values of w relative to n. If w/log n = (log log n)O(1), query time (log log log n)O(1) is achieved, and if additionally w/log n ≥ (log log n)1+ε for some fixed ε > 0, the query time is constant. For both of these special cases, the best previous upper bound was O(log log n). A new lower bound is also observed.

Part of this work was carried out while the author held a visiting position at the Department of Computer Science, University of Copenhagen, Denmark.

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Authors and Affiliations

  1. Max-Planck-Institut für Informatik, D-66123, Saarbrücken, Germany

    Torben Hagerup

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  1. Torben Hagerup
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Kim G. Larsen Sven Skyum Glynn Winskel

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© 1998 Springer-Verlag Berlin Heidelberg

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Hagerup, T. (1998). Simpler and faster dictionaries on the AC0 RAM. In: Larsen, K.G., Skyum, S., Winskel, G. (eds) Automata, Languages and Programming. ICALP 1998. Lecture Notes in Computer Science, vol 1443. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0055042

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  • DOI: https://doi.org/10.1007/BFb0055042

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  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-64781-2

  • Online ISBN: 978-3-540-68681-1

  • eBook Packages: Springer Book Archive

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