Title
Approximating edit distance efficiently
Abstract
Edit distance has been extensively studied for the past several years. Nevertheless, no linear-time algorithm is known to compute the edit distance between two strings, or even to approximate it to within a modest factor. Furthermore, for various natural algorithmic problems such as low-distortion embeddings into normed spaces, approximate nearest-neighbor schemes, and sketching algorithms, known results for the edit distance are rather weak. We develop algorithms that solve gap versions of the edit distance problem: given two strings of length n with the promise that their edit distance is either at most k or greater than \ell, decide which of the two holds. We present two sketching algorithms for gap versions of edit distance. Our first algorithm solves the k vs.(kn)^{{2 \mathord{\left/ {\vphantom {2 3}} \right. \kern-\nulldelimiterspace} 3}} gap problem, using a constant size sketch. A more involved algorithm solves the stronger k vs. \ell gap problem, where \ell can be as small as O(k虏) 驴 still with a constant sketch 驴 but works only for strings that are mildly "non-repetitive". Finally, we develop an n^{{3 \mathord{\left/ {\vphantom {3 7}} \right. \kern-\nulldelimiterspace} 7}}-approximation quasi-linear time algorithm for edit distance, improving the previous best factor of n^{{3 \mathord{\left/ {\vphantom {3 4}} \right. \kern-\nulldelimiterspace} 4}} [5]; if the input strings are assumed to be non-repetitive, then the approximation factor can be strengthened to n^{{1 \mathord{\left/ {\vphantom {1 3}} \right. \kern-\nulldelimiterspace} 3}}.
Year
DOI
Venue
2004
10.1109/FOCS.2004.14
FOCS
Keywords
Field
DocType
approximation theory,computational complexity,string matching,approximate nearest-neighbor schemes,approximation factor,approximation quasilinear time algorithm,edit distance approximation,gap versions,low-distortion embeddings,natural algorithmic problems,nonrepetitive strings,sketching algorithms
String-to-string correction problem,Edit distance,String searching algorithm,Discrete mathematics,Combinatorics,Wagner–Fischer algorithm,Approximation theory,Jaro–Winkler distance,Damerau–Levenshtein distance,Mathematics,Computational complexity theory
Conference
ISSN
ISBN
Citations 
0272-5428
0-7695-2228-9
48
PageRank 
References 
Authors
1.99
19
4
Name
Order
Citations
PageRank
Ziv Bar-Yossef11776118.00
Jayram, T.S.2613.47
Robert Krauthgamer31417103.80
Ravi Kumar4139321642.48