From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Sun, 10 Dec 2023 06:00:16 +0000 (+0100)
Subject: Day 10: quite ugly solution, does not work on examples of part 2
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=aoc.git;a=commitdiff_plain;h=0e9a2132dee3b812571f5506794af300aa1d1d15

Day 10: quite ugly solution, does not work on examples of part 2
---

diff --git a/2023/19.pl b/2023/19.pl
new file mode 100755
index 0000000..f6da134
--- /dev/null
+++ b/2023/19.pl
@@ -0,0 +1,72 @@
+#!/usr/bin/perl -w
+
+use v5.38;
+use experimental 'multidimensional', 'for_list', 'builtin';
+use builtin 'indexed';
+use List::Util;
+use Y::AoC::Task;
+$; = ';';
+# t;
+
+my @map = map { chomp; [ split //, ".$_." ] } <>;
+push @map, [ ('.') x @map ];
+unshift @map, [ ('.') x @map ];
+my $xmax = $#{$map[0]};
+my $ymax = $#map;
+
+my ($sx, $sy);
+for my $x (0 .. $xmax) {
+for my $y (0 .. $ymax) {
+	next if $map[$y][$x] ne 'S';
+	$sx = $x; $sy = $y;
+} }
+
+say "starting at $sx, $sy";
+
+my %dirs = (
+	'|' => [ 0, -1,  0,  1],
+	'-' => [-1,  0,  1,  0],
+	'J' => [-1,  0,  0, -1],
+	'L' => [ 1,  0,  0, -1],
+	'F' => [ 1,  0,  0,  1],
+	'7' => [-1,  0,  0,  1],
+);
+
+if ($map[$sy][$sx-1] eq '-' && $map[$sy][$sx+1] eq '-') {
+	$map[$sy][$sx] = '-';
+} elsif ($map[$sy+1][$sx] eq '|' && $map[$sy-1][$sx] eq '|') {
+	$map[$sy][$sx] = '|';
+} elsif ($map[$sy][$sx-1] eq '-' && $map[$sy-1][$sx] eq '|') {
+	$map[$sy][$sx] = 'J';
+} elsif ($map[$sy][$sx-1] eq '-' && $map[$sy+1][$sx] eq '|') {
+	$map[$sy][$sx] = '7';
+} elsif ($map[$sy][$sx+1] eq '-' && $map[$sy-1][$sx] eq '|') {
+	$map[$sy][$sx] = 'L';
+} elsif ($map[$sy][$sx+1] eq '-' && $map[$sy+1][$sx] eq '|') {
+	$map[$sy][$sx] = 'F';
+}
+
+my %seen;
+my $len = 0;
+my ($px, $py);
+while (!$seen{$sx,$sy}++) {
+	my @d = $dirs{ $map[$sy][$sx] }->@*;
+	say "map: $map[$sy][$sx] @d";
+	if (!defined($px) || ($px != $d[0] || $py != $d[1])) {
+		say "first";
+		$sx += $d[0];
+		$sy += $d[1];
+		$px = -$d[0];
+		$py = -$d[1];
+	} else {
+		say "second";
+		$sx += $d[2];
+		$sy += $d[3];
+		$px = -$d[2];
+		$py = -$d[3];
+	}
+	++$len;
+	say "at $sx $sy $map[$sy][$sx] from $px $py len $len";
+}
+
+say $len/2;
diff --git a/2023/20.pl b/2023/20.pl
new file mode 100755
index 0000000..c6d299a
--- /dev/null
+++ b/2023/20.pl
@@ -0,0 +1,101 @@
+#!/usr/bin/perl -w
+
+use v5.38;
+use experimental 'multidimensional', 'for_list', 'builtin';
+use builtin 'indexed';
+use List::Util;
+use Y::AoC::Task;
+$; = ';';
+# t;
+
+my @map = map { chomp; [ split //, ".$_." ] } <>;
+push @map, [ ('.') x @{ $map[0]} ];
+unshift @map, [ ('.') x @{$map[0]} ];
+my $xmax = $#{$map[0]};
+my $ymax = $#map;
+
+my ($sx, $sy);
+for my $x (0 .. $xmax) {
+for my $y (0 .. $ymax) {
+	next if $map[$y][$x] ne 'S';
+	$sx = $x; $sy = $y;
+} }
+
+
+my %dirs = (
+	'|' => [ 0, -1,  0,  1],
+	'-' => [-1,  0,  1,  0],
+	'J' => [-1,  0,  0, -1],
+	'L' => [ 1,  0,  0, -1],
+	'F' => [ 1,  0,  0,  1],
+	'7' => [-1,  0,  0,  1],
+);
+
+
+if ($map[$sy][$sx-1] eq '-' && $map[$sy][$sx+1] eq '-') {
+	$map[$sy][$sx] = '-';
+} elsif ($map[$sy+1][$sx] eq '|' && $map[$sy-1][$sx] eq '|') {
+	$map[$sy][$sx] = '|';
+} elsif ($map[$sy][$sx-1] eq '-' && $map[$sy-1][$sx] eq '|') {
+	$map[$sy][$sx] = 'J';
+} elsif ($map[$sy][$sx-1] eq '-' && $map[$sy+1][$sx] eq '|') {
+	$map[$sy][$sx] = '7';
+} elsif ($map[$sy][$sx+1] eq '-' && $map[$sy-1][$sx] eq '|') {
+	$map[$sy][$sx] = 'L';
+} elsif ($map[$sy][$sx+1] eq '-' && $map[$sy+1][$sx] eq '|') {
+	$map[$sy][$sx] = 'F';
+}
+
+say "starting at $sx, $sy $map[$sy][$sx]";
+my %seen;
+my $len = 0;
+my ($px, $py);
+while (!$seen{$sx,$sy}++) {
+	my @d = $dirs{ $map[$sy][$sx] }->@*;
+	if (!defined($px) || ($px != $d[0] || $py != $d[1])) {
+		$sx += $d[0];
+		$sy += $d[1];
+		$px = -$d[0];
+		$py = -$d[1];
+	} else {
+		$sx += $d[2];
+		$sy += $d[3];
+		$px = -$d[2];
+		$py = -$d[3];
+	}
+	++$len;
+}
+
+say "loop len ", $len/2;
+
+my $sum;
+for my $x (0 .. $xmax) {
+	my $in = 0;
+	my $left = 0;
+	for my $y (0 .. $ymax) {
+		if ($seen{$x,$y}) {
+			my $pt = $map[$y][$x];
+			if ($pt eq '-') {
+				$in = !$in;
+			} elsif ($pt eq '7') {
+				$left = 1;
+			} elsif ($pt eq 'F') {
+				$left = -1;
+			} elsif ($pt eq 'J') {
+				if ($left == -1) {
+					$in = !$in;
+				}
+			} elsif ($pt eq 'L') {
+				if ($left == 1) {
+					$in = !$in;
+				}
+			}
+			say "$x $y in $in left $left";
+		} elsif ($in) {
+			say "$x $y inside";
+			$sum++;
+		}
+	}
+}
+
+say $sum;