Day 21: shortened version

diff --git a/2024/41.pl b/2024/41.pl
index 0f0d5b2b651de84e1d8f8bd2503355aa8da3c11e..32de888aa5a1e457f23069427ff622d4991d848b 100755 (executable)
--- a/2024/41.pl
+++ b/2024/41.pl
@@ -3,35 +3,16 @@
 use v5.40;
 use List::Util qw(min uniq);
 
-my %npad = (
-       0 => [ 1, 3 ],
-       A => [ 2, 3 ],
-       1 => [ 0, 2 ],
-       2 => [ 1, 2 ],
-       3 => [ 2, 2 ],
-       4 => [ 0, 1 ],
-       5 => [ 1, 1 ],
-       6 => [ 2, 1 ],
-       7 => [ 0, 0 ],
-       8 => [ 1, 0 ],
-       9 => [ 2, 0 ],
-       'gap' => 'down',
-);
-my %dpad = (
-       '^' => [ 1, 0 ],
-       'A' => [ 2, 0 ],
-       '<' => [ 0, 1 ],
-       'v' => [ 1, 1 ],
-       '>' => [ 2, 1 ],
-       'gap' => 'up',
-);
+sub make_pad {
+       my $i = 0;
+       return map { $_ => [ $i % 3, int($i++ / 3) ]  } split //, shift;
+}
 
-sub min_len { min map { length } @_ };
-sub min_str { my $l = min_len(@_); uniq grep { length == $l } @_ };
+my %npad = make_pad('789456123_0A');
+my %dpad = make_pad('_^A<v>');
 
 sub moves {
        my ($from, $to, $pad) = @_;
-       my $rv;
        my $pos = $pad->{$from};
        my $dpos = $pad->{$to};
 
@@ -39,26 +20,20 @@ sub moves {
        my ($dx, $dy) = ($dpos->[0]-$pos->[0], $dpos->[1]-$pos->[1]);
        my $xs = $dx > 0 ? '>' x $dx : '<' x -$dx;
        my $ys = $dy > 0 ? 'v' x $dy : '^' x -$dy;
+       my $spc = $pad->{_};
        push @moves, $xs.$ys.'A'
-               if ($pad->{gap} eq 'down' && ($dpos->[0] > 0 || $pos->[1] < 3))
-               || ($pad->{gap} eq 'up'   && ($dpos->[0] > 0 || $pos->[1] > 0));
+               if $dpos->[0] != $spc->[0] || $pos->[1] != $spc->[1];
        push @moves, $ys.$xs.'A'
-               if ($pad->{gap} eq 'down' && ($dpos->[1] < 3 || $pos->[0] > 0))
-               || ($pad->{gap} eq 'up'   && ($dpos->[1] > 0 || $pos->[0] > 0));
-       return uniq @moves;
+               if $dpos->[1] != $spc->[1] || $pos->[0] != $spc->[0];
+       return @moves;
 }
 
 my %shortest;
 sub shortest {
        my ($pad) = @_;
        for my $k1 (keys %$pad) {
-               next if length $k1 > 1;
-               $shortest{"$k1$k1"} = [ 'A' ];
                for my $k2 (keys %$pad) {
-                       next if length $k2 > 1;
-                       $shortest{"$k1$k2"} = [
-                               min_str(moves($k1, $k2, $pad))
-                       ] if $k1 ne $k2;
+                       $shortest{"$k1$k2"} = [ moves($k1, $k2, $pad) ];
                }
        }
 }
@@ -77,7 +52,7 @@ sub prev_keypad {
                @rv = @nrv;
                $src = $dst;
        }
-       return min_str(@rv);
+       return @rv;
 }
 
 my $sum;
@@ -89,7 +64,8 @@ while (<>) {
                for my $str (@strs) {
                        push @ns, prev_keypad($str);
                }
-               @strs = min_str(@ns);
+               my $l = min map { length } @ns;
+               @strs = uniq grep { length == $l } @ns;
        }
        my $l = length($strs[0]);
        my ($n) = /\d+/g;

diff --git a/2024/42.pl b/2024/42.pl
index b6f3aafa99e1470a47b338a8e8c05014144e7ac4..be80aaf6940d649e52d7d414c40f62e487ae4ce6 100755 (executable)
--- a/2024/42.pl
+++ b/2024/42.pl
@@ -1,37 +1,18 @@
 #!/usr/bin/perl -w
 
 use v5.40;
-use List::Util qw(min uniq);
+use List::Util qw(min);
 
-my %npad = (
-       0 => [ 1, 3 ],
-       A => [ 2, 3 ],
-       1 => [ 0, 2 ],
-       2 => [ 1, 2 ],
-       3 => [ 2, 2 ],
-       4 => [ 0, 1 ],
-       5 => [ 1, 1 ],
-       6 => [ 2, 1 ],
-       7 => [ 0, 0 ],
-       8 => [ 1, 0 ],
-       9 => [ 2, 0 ],
-       'gap' => 'down',
-);
-my %dpad = (
-       '^' => [ 1, 0 ],
-       'A' => [ 2, 0 ],
-       '<' => [ 0, 1 ],
-       'v' => [ 1, 1 ],
-       '>' => [ 2, 1 ],
-       'gap' => 'up',
-);
+sub make_pad {
+       my $i = 0;
+       return map { $_ => [ $i % 3, int($i++ / 3) ]  } split //, shift;
+}
 
-sub min_len { min map { length } @_ };
-sub min_str { my $l = min_len(@_); uniq grep { length == $l } @_ };
+my %npad = make_pad('789456123_0A');
+my %dpad = make_pad('_^A<v>');
 
 sub moves {
        my ($from, $to, $pad) = @_;
-       my $rv;
        my $pos = $pad->{$from};
        my $dpos = $pad->{$to};
 
@@ -39,26 +20,20 @@ sub moves {
        my ($dx, $dy) = ($dpos->[0]-$pos->[0], $dpos->[1]-$pos->[1]);
        my $xs = $dx > 0 ? '>' x $dx : '<' x -$dx;
        my $ys = $dy > 0 ? 'v' x $dy : '^' x -$dy;
+       my $spc = $pad->{_};
        push @moves, $xs.$ys.'A'
-               if ($pad->{gap} eq 'down' && ($dpos->[0] > 0 || $pos->[1] < 3))
-               || ($pad->{gap} eq 'up'   && ($dpos->[0] > 0 || $pos->[1] > 0));
+               if $dpos->[0] != $spc->[0] || $pos->[1] != $spc->[1];
        push @moves, $ys.$xs.'A'
-               if ($pad->{gap} eq 'down' && ($dpos->[1] < 3 || $pos->[0] > 0))
-               || ($pad->{gap} eq 'up'   && ($dpos->[1] > 0 || $pos->[0] > 0));
-       return uniq @moves;
+               if $dpos->[1] != $spc->[1] || $pos->[0] != $spc->[0];
+       return @moves;
 }
 
 my %shortest;
 sub shortest {
        my ($pad) = @_;
        for my $k1 (keys %$pad) {
-               next if length $k1 > 1;
-               $shortest{"$k1$k1"} = [ 'A' ];
                for my $k2 (keys %$pad) {
-                       next if length $k2 > 1;
-                       $shortest{"$k1$k2"} = [
-                               min_str(moves($k1, $k2, $pad))
-                       ] if $k1 ne $k2;
+                       $shortest{"$k1$k2"} = [ moves($k1, $k2, $pad) ];
                }
        }
 }
@@ -77,7 +52,7 @@ sub prev_keypad {
                @rv = @nrv;
                $src = $dst;
        }
-       return min_str(@rv);
+       return @rv;
 }
 
 my %cache;