32 lines
1.1 KiB
Plaintext
32 lines
1.1 KiB
Plaintext
From: tseaver at palladion.com (Tres Seaver)
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Date: Fri, 23 Apr 1999 08:05:09 -0500
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Subject: Time complexity of dictionary insertions
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References: <371F2125.BEC5F892@fzi.de> <7fo08u$4j2$1@nnrp1.dejanews.com>
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Message-ID: <37207005.1CC60E1B@palladion.com>
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X-UID: 935
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tim_one at email.msn.com wrote:
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>
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> In article <371F2125.BEC5F892 at fzi.de>,
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> Oliver Ciupke <ciupke at fzi.de> wrote:
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> > As I understood from the Python documentation, dictionaries are
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> > implemented as extensible hash tables.
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>
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> Yes.
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>
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> > What I didn't find either in the references or in the FAQ is: what is
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> > the actual time complexity for an insertion into a dictionary?
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>
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> Min O(1), Max O(N), Ave O(1). If the hash function is doing a terrible job
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> (e.g. maps every key to the same hash value), make those all O(N).
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C++ STL junkies know this as "amortized constant time".
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=========================================================
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Tres Seaver tseaver at palladion.com 713-523-6582
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Palladion Software http://www.palladion.com
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