Day 14: slightly polished solution

diff --git a/2022/28.pl b/2022/28.pl
index 4af8d295fad90360bfb030f44824330100bb3bf3..1881f8e6a2ccead46868b40699396a1a2d02dce6 100755 (executable)
--- 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;