I'd be interested to see that.

#!/usr/bin/perl

use 5.010;

use strict;
use warnings;

my $MINIMIZE_WATER = 1;

my $X = 0;
my $Y = 1;
my $Z = 2;
my $Water = 3;
my $Move = 4;
my $Previous = 5;
my $MoveCount = 6;

my @trans = ('S -> X', 'S -> Y', 'X -> Y', 'X -> Z', 'Y -> X', 'Y -> Z
+',
             'Z -> X', 'Z -> Y', 'X -> S', 'Y -> S');

my ($Target, @LIMITS) = @ARGV;
$LIMITS[$Z] //= ~0;

package State;

sub new {
    my $class = shift;
    bless [@_], $class;
}

sub pour {
    my $self = shift;
    my ($from, $to) = @_;

    if ($self->[$from] + $self->[$to] <= $LIMITS[$to]) {
        $self->[$to] += $self->[$from];
        $self->[$from] = 0;
    }
    else {
        $self->[$from] -= $LIMITS[$to] - $self->[$to];
        $self->[$to] = $LIMITS[$to]
    }
}

sub fill {
    my $self = shift;
    my $to = shift;
    $self->[$Water] += $LIMITS[$to] - $self->[$to];
    $self->[$to] = $LIMITS[$to];
}
             
sub empty {
    my $self = shift;
    my $from = shift;
    $self->[$from] = 0;
}

sub trans {
    my $self = shift; 
    my $trans = shift; 
 
    my $New = State->new (@$self);
    $New->[$Move] = $trans;
    $New->[$Previous] = $self;
    $New->[$MoveCount] = $self->[$MoveCount] + 1;

    given ($trans) {
        when ('S -> X') {$New->fill($X)}
        when ('S -> Y') {$New->fill($Y)}
        when ('X -> Y') {$New->pour($X, $Y)}
        when ('X -> Z') {$New->pour($X, $Z)}
        when ('Y -> X') {$New->pour($Y, $X)}
        when ('Y -> Z') {$New->pour($Y, $Z)}
        when ('Z -> X') {$New->pour($Z, $X)}
        when ('Z -> Y') {$New->pour($Z, $Y)}
        when ('X -> S') {$New->empty($X)}
        when ('Y -> S') {$New->empty($Y)}
        default {die $trans}
    }
    $New;
}
 
sub id {     
    my $self = shift;
    join ",", @$self[$X,$Y,$Z]
}
    
sub print {
    my $self = shift;
    return unless $self->[$Move];
    $self->[$Previous]->print;
    printf "%2d. %s (X = %2d, Y = %2d, Z = %2d; Water = %2d)\n",
            @$self[$MoveCount, $Move, $X, $Y, $Z, $Water];
}
    
package main;
    
foreach my $MINIMIZE_WATER (0, 1) {
    my @QUEUE;
    my %SEEN;
        
    my $start = State->new(0, 0, 0, 0, undef, undef, 0);
    $SEEN{$start->id}++;
        
    push @QUEUE, $start;
        
  LOOP:
    while (1) {
        my $state = shift @QUEUE;
        foreach my $trans (@trans) {
            my $new = $state->trans($trans);
            next if $SEEN{$new->id}++;
            if ($new->[$Z] == $Target) {
                $new->print;
                last LOOP;
            }
            push @QUEUE, $new;
            if ($MINIMIZE_WATER) {
                @QUEUE = sort {$a->[$Water] <=> $b->[$Water] ||
                               $a->[$MoveCount] <=> $b->[$MoveCount]} 
+@QUEUE;
            }
        }
    }
    say "----";
}

__END__
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.