Well, it certainly takes a while to build the db the first time... (over 15 mins so far... maybe LevenshteinXS isn't quite right on Win?) Here's my offing that was written for clarity, rather than efficiency. Then again, maybe I'll say it's optimized for startup time, rather than solution time... who likes those long 'loading...' screens, anyway?

Update:I should have realized that I'm using the yawl-0.3.2 word list, and the time to build the db is probably affected by that! 

use strict;
use warnings;

use List::Compare;
use Benchmark qw( cmpthese );

my $lword = shift || 'love';
my $rword = shift || 'hate';

die unless length($rword) == length($lword);
my $length = length($lword);

my $wordlist;
open(FH,'word.list') or die;
while(<FH>) {
    chomp;
    undef($wordlist->{lc $_}) if length($_) == $length;
}

print solo($lword,$rword);

#cmpthese( ... );

sub solo {
    my ( $rdepth,$ldepth,$rex,$lex ) = (0,0,1,1);
    my $left   = { $_[0] => [$_[0]] };
    my $right  = { $_[1] => [$_[1]] };

    while ( 1 ) {
        # compare the intersection of the leaf nodes
        my $lc = List::Compare->new( {
            lists    => [ [keys %$left], [keys %$right] ],
            accelerated => 1,
            unsorted => 1,
        } );
        my @int = $lc->get_intersection();
        if ( @int ) {
            my $solve = shift @int;
            pop @{$right->{$solve}};
            return join("\n", @{$left->{$solve}}, reverse @{$right->{$
+solve}}) . "\n";
        }

        # pick a side to expand the search in
        if ( $lex && $rdepth > $ldepth ) {
            $lex = expandTree($left,++$ldepth);
        }
        elsif ( $rex ) {
            $rex = expandTree($right,++$rdepth);
        }
        else {
            return "No solution.";
        }
    
    }
}

sub expandTree {
    my ($tree, $depth) = @_;
    my ($word, $path, $expanded);
    while ( ($word, $path) = each %$tree ) {
        if ( @$path == $depth ) {
            for my $i (0..(length($word)-1) ) {
                for my $letter ( 'a'..'z' ) {
                    my $try = $word;
                    substr($try,$i,1) = $letter;
                    next if exists $tree->{$try};
                    if ( exists $wordlist->{$try} ) {
                        $tree->{$try} = [ @{$tree->{$word}}, $try ];
                        $expanded = 1;
                    }
                }
            }
        }
    }
    return $expanded;
}

[download]

--Solo

--
You said you wanted to be around when I made a mistake; well, this could be it, sweetheart.

In reply to Re: A Better Word Morph Builder by Solo
in thread A Better Word Morph Builder by Limbic~Region

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