A dictionary for approximate string search and longest prefix search
A dictionary for approximate string search and longest prefix search
复制标题
用于近似字符串搜索和最长前缀搜索的字典
DOI:
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发表时间:
2006
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通讯作者:
R. Panigrahy
中科院分区:
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作者:
Sreenivas Gollapudi;R. Panigrahy
In this paper we propose a dictionary data structure for string search with errors where the query string may didiffer from the expected matching string by a few edits. This data structure can also be used to find the database string with the longest common prefix with few errors. Specifically, with a database of <i>n</i> random strings, each of length of <i>O</i>(<i>m</i>), we show how to perform string search on a query string that differs from its closest match by <i>k</i> edits using a data structure of linear size and query time equal to <i>Õ</i>(log <i>n</i> <sup>2 log <i>n</i> <i>k</i>log <sub><i>a</i></sub> 2<i>m</i></sup> over 2<i>m</i>). This means that if <i>k</i> < <i>m</i> over log <sub><i>a</i></sub> 2<i>m</i> log <i>n</i>, then the query time is <i>Õ</i>(1). This is of significant in practice as there are several applications where <i>k</i> is small relative to <i>m</i>. Our approach converts strings into bit vectors so that similar strings can map to similar bit vectors with small hamming distance. A simple reduction can be used to obtain similar results for approximate longest prefix search.