From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Thu, 14 Dec 2023 07:04:10 +0000 (+0100)
Subject: Day 14: ugly but fast written solution
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=aoc.git;a=commitdiff_plain;h=9df28e43f93ba69cba3f7f56dbb1b77235ad7413

Day 14: ugly but fast written solution
---

diff --git a/2023/27.pl b/2023/27.pl
new file mode 100755
index 0000000..ab6cbcd
--- /dev/null
+++ b/2023/27.pl
@@ -0,0 +1,31 @@
+#!/usr/bin/perl -w
+
+use v5.38;
+
+my @map = map { chomp; [ split // ] } <>;
+my $xmax = $#{ $map[0] };
+my $ymax = $#map;
+
+my $sum;
+my $retry = 1;
+while ($retry) {
+	$retry = 0;
+for my $y (1 .. $ymax) {
+	for my $x (0 .. $xmax) {
+		if ($map[$y][$x] eq 'O' && $map[$y-1][$x] eq '.') {
+			$map[$y-1][$x] = 'O';
+			$map[$y][$x] = '.';
+			$retry = 1;
+		}
+	}
+}
+}
+	
+say join('', @$_) for @map;
+
+for my $y (0 .. $ymax) {
+	for my $x (0 .. $xmax) {
+		$sum += $ymax + 1 - $y if $map[$y][$x] eq 'O';
+	}
+}
+say $sum;
diff --git a/2023/28.pl b/2023/28.pl
new file mode 100755
index 0000000..7135ca5
--- /dev/null
+++ b/2023/28.pl
@@ -0,0 +1,92 @@
+#!/usr/bin/perl -w
+
+use v5.38;
+
+my @map = map { chomp; [ split // ] } <>;
+my $xmax = $#{ $map[0] };
+my $ymax = $#map;
+
+my %seen;
+my @rounds;
+my $round;
+while (1) {
+	$round++;
+	my $retry;
+	$retry = 1;
+	while ($retry) {
+		$retry = 0;
+		for my $y (1 .. $ymax) {
+			for my $x (0 .. $xmax) {
+				if ($map[$y][$x] eq 'O' && $map[$y-1][$x] eq '.') {
+					$map[$y-1][$x] = 'O';
+					$map[$y][$x] = '.';
+					$retry = 1;
+				}
+			}
+		}
+	}
+	$retry = 1;
+	while ($retry) {
+		$retry = 0;
+		for my $x (1 .. $xmax) {
+			for my $y (0 .. $ymax) {
+				if ($map[$y][$x] eq 'O' && $map[$y][$x-1] eq '.') {
+					$map[$y][$x-1] = 'O';
+					$map[$y][$x] = '.';
+					$retry = 1;
+				}
+			}
+		}
+	}
+	$retry = 1;
+	while ($retry) {
+		$retry = 0;
+		for my $y (reverse 0 .. $ymax-1) {
+			for my $x (0 .. $xmax) {
+				if ($map[$y][$x] eq 'O' && $map[$y+1][$x] eq '.') {
+					$map[$y+1][$x] = 'O';
+					$map[$y][$x] = '.';
+					$retry = 1;
+				}
+			}
+		}
+	}
+	$retry = 1;
+	while ($retry) {
+		$retry = 0;
+		for my $x (reverse 0 .. $xmax-1) {
+			for my $y (0 .. $ymax) {
+				if ($map[$y][$x] eq 'O' && $map[$y][$x+1] eq '.') {
+					$map[$y][$x+1] = 'O';
+					$map[$y][$x] = '.';
+					$retry = 1;
+				}
+			}
+		}
+	}
+		
+	# say join('', @$_) for @map;
+
+	my $sum;
+	for my $y (0 .. $ymax) {
+		for my $x (0 .. $xmax) {
+			$sum += $ymax + 1 - $y if $map[$y][$x] eq 'O';
+		}
+	}
+	say $sum;
+	$rounds[$round] = $sum;
+	say "round $round sum $sum";
+	my $map = join("\n", map { join('', @$_) } @map);
+	if ($seen{$map}) {
+		say "round $round seen also at $seen{$map}";
+		my $period = $round - $seen{$map};
+		my $total = 1000000000;
+		$total -= $round;
+		$total %= $period;
+		say "looking at ", $round - $period + $total;
+		say $rounds[$round-$period+$total];
+		last;
+	}
+	$seen{$map} = $round;
+}
+