LCS::BV - Bit Vector (BV) implementation of the Longest Common Subsequence (LCS) Algorithm
use LCS::BV; $object = LCS::BV->new; @lcs = $object->LCS(\@a,\@b); $llcs = $object->LLCS(\@a,\@b); $positions = $object->prepare(\@a); $llcs = $object->LLCS_prepared($positions,\@b);
LCS::BV implements Algorithm::Diff using bit vectors and is faster in most cases, especially on strings with a length shorter than the used wordsize of the hardware (32 or 64 bits).
Creates a new object which maintains internal storage areas for the LCS computation. Use one of these per concurrent LCS() call.
Return the length of a Longest Common Subsequence, taking two arrayrefs as method arguments. It returns an integer.
Finds a Longest Common Subsequence, taking two arrayrefs as method arguments. It returns an array reference of corresponding indices, which are represented by 2-element array refs.
For comparison of the same sequence @a many times against different sequences @b it can be faster to prepare @a. It returns a hashref of positions. This works only on object mode.
Return the length of a Longest Common Subsequence, with one side prepared. It returns an integer. It is two times faster than LLCS().
None by design.
Until release of version 1.00 the included methods, names of methods and their interfaces are subject to change.
Beginning with version 1.00 the specification will be stable, i.e. not changed between major versions.
H. Hyyroe. A Note on Bit-Parallel Alignment Computation. In M. Simanek and J. Holub, editors, Stringology, pages 79-87. Department of Computer Science and Engineering, Faculty of Electrical Engineering, Czech Technical University, 2004.
Intel Core i7-4770HQ Processor Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2 4 Cores, 8 Threads 2.20 - 3.40 GHz 6 MB Cache 16 GB DDR3 RAM
LCS-BV/xt$ perl 50_diff_bench.t
LCS: Algorithm::Diff, Algorithm::Diff::XS, LCS, LCS::BV
LCS: [Chrerrplzon] [Choerephon]
Rate LCS:LCS AD:LCSidx AD:XS:LCSidx LCS:BV:LCS LCS:LCS 9225/s -- -72% -87% -88% AD:LCSidx 33185/s 260% -- -53% -58% AD:XS:LCSidx 70447/s 664% 112% -- -12% LCS:BV:LCS 79644/s 763% 140% 13% --
LCS: [qw/a b d/ x 50], [qw/b a d c/ x 50]
Rate LCS:LCS AD:LCSidx LCS:BV:LCS AD:XS:LCSidx LCS:LCS 49.5/s -- -37% -96% -99% AD:LCSidx 79.0/s 60% -- -94% -98% LCS:BV:LCS 1255/s 2434% 1488% -- -69% AD:XS:LCSidx 4073/s 8124% 5052% 224% --
LLCS: [Chrerrplzon] [Choerephon]
Rate LCS:LLCS AD:LCS_length AD:XS:LCS_length LCS:BV:LLCS LCS:LLCS 11270/s -- -70% -70% -92% AD:LCS_length 37594/s 234% -- -1% -75% AD:XS:LCS_length 38059/s 238% 1% -- -74% LCS:BV:LLCS 148945/s 1222% 296% 291% --
LLCS: [qw/a b d/ x 50], [qw/b a d c/ x 50]
Rate LCS:LLCS AD:LCS_length AD:XS:LCS_length LCS:BV:LLCS LCS:LLCS 50.0/s -- -37% -37% -98% AD:LCS_length 79.2/s 58% -- -1% -97% AD:XS:LCS_length 79.8/s 60% 1% -- -97% LCS:BV:LLCS 2357/s 4614% 2874% 2853% --
http://github.com/wollmers/LCS-BV
Algorithm::Diff LCS LCS::Tiny
Helmut Wollmersdorfer <helmut.wollmersdorfer@gmail.com>
Copyright 2014-2020 by Helmut Wollmersdorfer
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install LCS::BV, copy and paste the appropriate command in to your terminal.
cpanm
cpanm LCS::BV
CPAN shell
perl -MCPAN -e shell install LCS::BV
For more information on module installation, please visit the detailed CPAN module installation guide.