Algorithm::LCS - Fast (XS) implementation of the Longest Common Subsequence (LCS) Algorithm
use Algorithm::LCS; $alg = Algorithm::LCS->new; @lcs = $alg->LCS(\@a,\@b); $cb = $alg->callback(@b); # closure @lcs = $cb->(\@a); # same result as prior LCS() call
Algorithm::LCS reimplements Algorithm::Diff's core loop in XS, and provides a simple OO interface to it.
Extract from the Algorithm::Diff v1.15 manpage:
The algorithm is that described in I<A Fast Algorithm for Computing Longest Common Subsequences>, CACM, vol.20, no.5, pp.350-353, May 1977, with a few minor improvements to improve the speed.
Creates a new object which maintains internal storage areas for the LCS computation. Use one of these per concurrent LCS() call.
Send @lines to a hashref containing elements of the form
value => [(increasing) list of matching indices]
Generates a closure capturing the object and line_map hash for @lines. Most useful when computing multiple LCSs against a single file.
Finds a Longest Common Subsequence, taking two arrayrefs as method arguments. In scalar context the return value is the length of the subsequence. In list context it yields a list of corresponding indices, which are represented by 2-element array refs. See the Algorithm::Diff manpage for more details.
None by design.
Joe Schaefer, <firstname.lastname@example.org>
Copyright 2003 by Joe Schaefer
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.