From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Sun, 20 Dec 2020 09:22:08 +0000 (+0100)
Subject: Day 20: manual coding, coding, coding
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=3dcbc8cbbed0a020192974ba29b73f0164b49ce2;p=aoc2020.git

Day 20: manual coding, coding, coding
---

diff --git a/39.pl b/39.pl
new file mode 100755
index 0000000..2b88a89
--- /dev/null
+++ b/39.pl
@@ -0,0 +1,75 @@
+#!/usr/bin/perl -w
+
+use strict;
+
+local $/ = "\n\n";
+
+sub invbits {
+	my ($in) = @_;
+	return (($in & 1) << 9)
+		| (($in & 2) << 7)
+		| (($in & 4) << 5)
+		| (($in & 8) << 3)
+		| (($in & 16) << 1)
+		| (($in & 32) >> 1)
+		| (($in & 64) >> 3)
+		| (($in & 128) >> 5)
+		| (($in & 256) >> 7)
+		| (($in & 512) >> 9);
+}
+
+my %tiles;
+my %sides;
+my %side2tiles;
+while (<>) {
+	my ($id, @rows) = split /\n/;
+	$id =~ s/Tile //;
+	$id =~ s/://;
+	@rows = map { y/#./10/; oct "0b$_" } @rows;
+	$tiles{$id} = \@rows;
+	$sides{$id} = [
+		$rows[0],
+		(($rows[0] & 1) << 9)
+		| (($rows[1] & 1) << 8)
+		| (($rows[2] & 1) << 7)
+		| (($rows[3] & 1) << 6)
+		| (($rows[4] & 1) << 5)
+		| (($rows[5] & 1) << 4)
+		| (($rows[6] & 1) << 3)
+		| (($rows[7] & 1) << 2)
+		| (($rows[8] & 1) << 1)
+		| (($rows[9] & 1) << 0),
+		$rows[9],
+		(($rows[0] & 512) >> 0)
+		| (($rows[1] & 512) >> 1)
+		| (($rows[2] & 512) >> 2)
+		| (($rows[3] & 512) >> 3)
+		| (($rows[4] & 512) >> 4)
+		| (($rows[5] & 512) >> 5)
+		| (($rows[6] & 512) >> 6)
+		| (($rows[7] & 512) >> 7)
+		| (($rows[8] & 512) >> 8)
+		| (($rows[9] & 512) >> 9),
+	];
+	print "Tile <$id> sides ", join(',', @{ $sides{$id} }), "\n";
+	for my $side (@{ $sides{$id} }) {
+		push @{ $side2tiles{$side} }, $id;
+		push @{ $side2tiles{invbits($side)} }, $id;
+	}
+}
+
+my %single_ids;
+for my $side (keys %side2tiles) {
+	print "side $side: ", join(',', @{ $side2tiles{$side} }), "\n";
+	# print "inv  ", invbits($side), "\n";
+	if (scalar @{ $side2tiles{$side} } == 1
+		&& scalar @{ $side2tiles{invbits($side)} } == 1) {
+		print "side $side of tile $side2tiles{$side}->[0] is single\n";
+		$single_ids{$side2tiles{$side}->[0]}++;
+	}
+	
+}
+
+my @corners = grep { $single_ids{$_} == 4 } keys %single_ids;
+print join('*', @corners), '=', eval join('*', @corners), "\n"
+
diff --git a/40.pl b/40.pl
new file mode 100755
index 0000000..df479d9
--- /dev/null
+++ b/40.pl
@@ -0,0 +1,158 @@
+#!/usr/bin/perl -w
+
+use strict;
+
+local $/ = "\n\n";
+
+sub rev {
+	my ($in) = @_;
+	return join('', reverse split //, $in);
+}
+
+
+my %tiles;
+my %sides;
+my %side2tiles;
+while (<>) {
+	my ($id, @rows) = split /\n/;
+	$id =~ s/Tile //;
+	$id =~ s/://;
+	$tiles{$id} = \@rows;
+	$sides{$id} = [
+		$rows[0],
+		join('', map { substr($_, -1, 1) } @rows),
+		rev($rows[-1]),
+		rev(join('', map { substr($_, 0, 1) } @rows)),
+	];
+	print "Tile <$id> sides ", join(' ', @{ $sides{$id} }), "\n";
+	my $i = 0;
+	for my $side (@{ $sides{$id} }) {
+		$side2tiles{$side}->{$id} = $i;
+		$side2tiles{rev($side)}->{$id} = $i+4;
+		$i++;
+	}
+}
+
+my $dim = 12;
+my $next = '###.#.#...';
+
+# my $dim = 3;
+# my $next = '#...##.#..';
+my $next_id = -1;
+my $map;
+my %seen;
+
+for my $y (0 .. $dim-1) {
+	my ($id) = grep { $_ != $next_id } keys %{ $side2tiles{$next} };
+	my $side = $side2tiles{$next}->{$id};
+	$map->[$y][0] = [ $id, $side ];
+	die "$id seen again\n"
+		if $seen{$id};
+	$seen{$id} = 1;
+	my $next_side = $side > 3
+		? (($side - 1) & 3)
+		: ($side + 1) & 3;
+	$next = $sides{$id}->[$next_side];
+	$next = rev($next) if $side > 3;
+	my $top_side = $side;
+	print "id=$id, side=$side, next_side=$next_side, top_side=$top_side, next=|$next|\n";
+	$next_id = $id;
+	
+	for my $x (1 .. $dim-1) {
+		($id) = grep { $_ != $next_id } keys %{ $side2tiles{$next} };
+		$side = $side2tiles{$next}->{$id};
+		die "$id seen again\n"
+			if $seen{$id};
+		$seen{$id} = 1;
+		my $top_side = ((($side & 3) + (($side >> 2) ? 1 : -1)) & 3) | (($side & 4) ^ 4);
+		$map->[$y][$x] = [ $id, $top_side ];
+		$next_side = (($side + 2) & 3);
+		$next = $sides{$id}->[$next_side];
+		$next = rev($next) if $side < 4;
+		$next_id = $id;
+		print "id=$id, side=$side, next_side=$next_side, top_side=$top_side, next=|$next|\n";
+	}
+
+	print "\n";
+
+	($next_id, $next_side) = @{ $map->[$y][0] };
+	$next = $sides{$next_id}->[($next_side + 2) & 3];
+	$next = rev($next) if $next_side < 4;
+	print "bottom side of $next_id = |$next|\n";
+}
+
+my $shortmap = '';
+for my $y (0 .. 8*$dim-1) {
+	my $y1 = 1 + ($y % 8);
+	for my $x (0 .. 8*$dim-1) {
+		my $x1 = 1 + ($x % 8);
+		my ($id, $or) = @{ $map->[int($y/8)][int($x/8)] };
+		my ($x2, $y2) = ($x1, $y1);
+		if ($or == 1) {
+			($x2, $y2) = (9-$y1, $x1);
+		} elsif ($or == 2) {
+			($x2, $y2) = (9-$x1, 9-$y1);
+		} elsif ($or == 3) {
+			($x2, $y2) = ($y1, 9-$x1);
+		} elsif ($or == 4) {
+			($x2, $y2) = (9-$x1, $y1);
+		} elsif ($or == 5) {
+			($x2, $y2) = (9-$y1, 9-$x1);
+		} elsif ($or == 6) {
+			($x2, $y2) = ($x1, 9-$y1);
+		} elsif ($or == 7) {
+			($x2, $y2) = ($y1, $x1);
+		}
+		$shortmap .= substr($tiles{$id}->[$y2], $x2, 1);
+	}
+	$shortmap .= "\n";
+}
+
+print join("\n", $shortmap), "\n";
+
+my $monster = join('[\.#\n]' x ($dim * 8 - 20 + 1), map { $a=$_; $a=~ s/\./[\.#]/g; $a } 
+	 '..................#.',
+	'#....##....##....###',
+	'.#..#..#..#..#..#...'
+);
+
+$monster = ".(?=$monster)";
+print "monster=$monster\n";
+
+for (1 .. 2) {
+	for (1 .. 4) {
+		my $count;
+		if (my $count =()= $shortmap =~ /($monster)/g) {
+			print "$count matches\n";
+			my $hashes =()= $shortmap =~ /#/g;
+			print "$hashes-$count*15=", $hashes-$count*15, "\n";
+			exit 0;
+		}
+		my $newmap = '';
+		for my $y (0 .. 8*$dim-1) {
+			for my $x (0 .. 8*$dim-1) {
+				print "$x,$y\n";
+				$newmap .= substr($shortmap,
+					$y + (8*$dim+1)*(8*$dim-$x-1), 1);
+			}
+			$newmap .= "\n";
+		}
+		print "\nRotate:\n$newmap\n";
+		$shortmap = $newmap;
+	}
+	my $newmap;
+	for my $y (0 .. 8*$dim-1) {
+		for my $x (0 .. 8*$dim-1) {
+			$newmap .= substr($shortmap,
+				$x + (8*$dim+1)*(8*$dim-$y-1), 1);
+		}
+		$newmap .= "\n";
+	}
+	$shortmap = $newmap;
+	print "\nFlip:\n$newmap\n";
+
+}
+
+		
+
+