16 lines
997 B
Text
16 lines
997 B
Text
This module implements a trie data structure. The term "trie" comes from the
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word retrieval, but is generally pronounced like "try". A trie is a tree
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structure (or directed acyclic graph), the nodes of which represent letters
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in a word. For example, the final lookup for the word 'bob' would look
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something like $ref->{'b'}{'o'}{'b'}{'00'} (the 00 being an end marker).
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Only nodes which would represent words in the trie exist, making the structure
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slightly smaller than a hash of the same data set.
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The advantages of the trie over other data storage methods is that lookup times
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are O(1) WRT the size of the index. For sparse data sets, it is probably not as
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efficient as performing a binary search on a sorted list, and for small files,
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it has a lot of overhead. The main advantage (at least from my perspective) is
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that it provides a relatively cheap method for finding a list of words in a
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large, dense data set which begin with a certain string.
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WWW: http://search.cpan.org/dist/Tree-Trie/
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