Year 2018

[aoc.git] / 2018 / 35.pl

diff --git a/2018/35.pl b/2018/35.pl
new file mode 100755 (executable)
index 0000000..bf04ec7
--- /dev/null
+++ b/2018/35.pl
@@ -0,0 +1,47 @@
+#!/usr/bin/perl -w
+
+use v5.36;
+use strict;
+use experimental 'multidimensional';
+
+my @map = map { chomp; [ split // ] } <>;
+
+my $rows = @map;
+my $cols = @{ $map[0] };
+
+my %total;
+for (1..10) {
+       %total = ();
+       my @nmap;
+       for my $y (0 .. $rows-1) {
+               my @row;
+               for my $x (0 .. $cols-1) {
+                       my %count = map { $_ => 0 } ('#', '|', '.');
+                       for my $neigh ([-1,-1], [0, -1], [1, -1],
+                               [-1, 0], [1, 0],
+                               [-1, 1], [0, 1], [1, 1]) {
+                               my $nx = $x + $neigh->[0];
+                               my $ny = $y + $neigh->[1];
+                               next if $nx < 0 || $nx >= $cols
+                                       || $ny < 0 || $ny >= $cols;
+                               $count{$map[$ny][$nx]}++;
+                       }
+                       my $self = $map[$y][$x];
+                       if ($self eq '.' && $count{'|'} >= 3) {
+                               $self = '|';
+                       } elsif ($self eq '|' && $count{'#'} >= 3) {
+                               $self = '#';
+                       } elsif ($self eq '#' &&
+                               ($count{'#'} == 0 || $count{'|'} == 0)) {
+                               $self = '.';
+                       }
+                       push @row, $self;
+                       $total{$self}++;
+               }
+               push @nmap, \@row;
+       }
+       @map = @nmap;
+       say map { join('', @$_, "\n") } @map;
+}
+
+say $total{"#"} * $total{'|'};