From 805d6da975d74ff6f4573235c979942a5bf64525 Mon Sep 17 00:00:00 2001
From: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Date: Wed, 14 Dec 2022 08:47:54 +0100
Subject: [PATCH] Day 14: slightly polished solution

---
 2022/28.pl | 53 +++++++++++++++++++----------------------------------
 1 file changed, 19 insertions(+), 34 deletions(-)

diff --git a/2022/28.pl b/2022/28.pl
index 4af8d29..1881f8e 100755
--- a/2022/28.pl
+++ b/2022/28.pl
@@ -2,57 +2,42 @@
 
 use v5.36;
 use strict;
-use experimental 'multidimensional';
+use experimental 'for_list';
 
 my @map;
 
-sub sgn($x) { $x > 0 ? 1 : $x < 0 ? -1 : 0 };
-
-my $maxy;
 while (<>) {
-	my ($x0, $y0);
 	my @list = /(\d+)/g;
+	my ($x0, $y0) = splice @list, 0, 2;
+	$map[$y0][$x0] = 1;
 
 	for my ($x, $y) (@list) {
-		if (!defined $x0) {
-			$x0 = $x; $y0 = $y;
-			$map[$y][$x] = 1;
-		} else {
-			while ($x0 != $x || $y0 != $y) {
-				$x0 += sgn($x-$x0);
-				$y0 += sgn($y-$y0);
-				$map[$y0][$x0] = 1;
-				$maxy = $y if !defined $maxy || $y > $maxy;
-			}
+		while ($x0 != $x || $y0 != $y) {
+			$x0 += $x <=> $x0;
+			$y0 += $y <=> $y0;
+			$map[$y0][$x0] = 1;
 		}
 	}
 }
+my $maxy = @map;
 
 my $units = 0;
-UNIT:
-while (1) {
-	my ($sx, $sy) = (500, 0);
-
-	while (1) {
-		if ($sy >= $maxy + 1) {
-			$map[$sy][$sx] = 2;
-			last;
-		} elsif (!$map[$sy+1][$sx]) {
-			$sy++;
-		} elsif (!$map[$sy+1][$sx-1]) {
-			$sx--;
-			$sy++;
-		} elsif (!$map[$sy+1][$sx+1]) {
-			$sx++;
-			$sy++;
+while (!$map[0][500]) {
+	my ($x, $y) = (500, 0);
+
+	while ($y < $maxy) {
+		if (!$map[$y+1][$x]) {
+			$y++;
+		} elsif (!$map[$y+1][$x-1]) {
+			$x--; $y++;
+		} elsif (!$map[$y+1][$x+1]) {
+			$x++; $y++;
 		} else {
-			last UNIT if $map[$sy][$sx];		
-			$map[$sy][$sx] = 2;
 			last;
 		}
 	}
+	$map[$y][$x] = 2;
 	$units++;
-	last if $sy == 0;
 }
 
 say $units;
-- 
2.43.0