From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Sat, 21 Dec 2024 11:40:53 +0000 (+0100)
Subject: Day 21: interesting task, quite complicated implementation
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=3463b129802fe203864e7b76dc9a87455681677c;p=aoc.git

Day 21: interesting task, quite complicated implementation
---

diff --git a/2024/41.pl b/2024/41.pl
new file mode 100755
index 0000000..0f0d5b2
--- /dev/null
+++ b/2024/41.pl
@@ -0,0 +1,99 @@
+#!/usr/bin/perl -w
+
+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 min_len { min map { length } @_ };
+sub min_str { my $l = min_len(@_); uniq grep { length == $l } @_ };
+
+sub moves {
+	my ($from, $to, $pad) = @_;
+	my $rv;
+	my $pos = $pad->{$from};
+	my $dpos = $pad->{$to};
+
+	my @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;
+	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));
+	push @moves, $ys.$xs.'A'
+		if ($pad->{gap} eq 'down' && ($dpos->[1] < 3 || $pos->[0] > 0))
+		|| ($pad->{gap} eq 'up'   && ($dpos->[1] > 0 || $pos->[0] > 0));
+	return uniq @moves;
+}
+
+my %shortest;
+sub shortest {
+	my ($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 $k2;
+		}
+	}
+}
+shortest(\%npad);
+shortest(\%dpad);
+
+sub prev_keypad {
+	my ($str) = @_;
+	my $src = 'A';
+	my @rv = '';
+	for my $dst (split //, $str) {
+		my @nrv;
+		for my $s ($shortest{"$src$dst"}->@*) {
+			push @nrv, map { "$_$s" } @rv;
+		}
+		@rv = @nrv;
+		$src = $dst;
+	}
+	return min_str(@rv);
+}
+
+my $sum;
+while (<>) {
+	chomp;
+	my @strs = ($_);
+	for (1 .. 3) {
+		my @ns;
+		for my $str (@strs) {
+			push @ns, prev_keypad($str);
+		}
+		@strs = min_str(@ns);
+	}
+	my $l = length($strs[0]);
+	my ($n) = /\d+/g;
+	$sum += $l*$n;
+}
+say $sum;
+
diff --git a/2024/42.pl b/2024/42.pl
new file mode 100755
index 0000000..b6f3aaf
--- /dev/null
+++ b/2024/42.pl
@@ -0,0 +1,105 @@
+#!/usr/bin/perl -w
+
+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 min_len { min map { length } @_ };
+sub min_str { my $l = min_len(@_); uniq grep { length == $l } @_ };
+
+sub moves {
+	my ($from, $to, $pad) = @_;
+	my $rv;
+	my $pos = $pad->{$from};
+	my $dpos = $pad->{$to};
+
+	my @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;
+	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));
+	push @moves, $ys.$xs.'A'
+		if ($pad->{gap} eq 'down' && ($dpos->[1] < 3 || $pos->[0] > 0))
+		|| ($pad->{gap} eq 'up'   && ($dpos->[1] > 0 || $pos->[0] > 0));
+	return uniq @moves;
+}
+
+my %shortest;
+sub shortest {
+	my ($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 $k2;
+		}
+	}
+}
+shortest(\%npad);
+shortest(\%dpad);
+
+sub prev_keypad {
+	my ($str) = @_;
+	my $src = 'A';
+	my @rv = '';
+	for my $dst (split //, $str) {
+		my @nrv;
+		for my $s ($shortest{"$src$dst"}->@*) {
+			push @nrv, map { "$_$s" } @rv;
+		}
+		@rv = @nrv;
+		$src = $dst;
+	}
+	return min_str(@rv);
+}
+
+my %cache;
+sub count_str {
+	my ($str, $n) = @_;
+	return length($str) if !$n;
+	return 1 if $str eq 'A';
+	my $sum;
+	$n--;
+	for my $str (split /A/, $str) {
+		$sum += $cache{"$str,$n"} //= min
+			map { count_str($_, $n) } prev_keypad($str.'A');
+	}
+	return $sum;
+}
+
+my $sum;
+while (<>) {
+	chomp;
+	my $l = count_str($_, 26);
+	my ($n) = /[1-9]\d+/g;
+	$sum += $l*$n;
+}
+say $sum;
+