Day 20: examining the input

[aoc.git] / 2023 / 39.pl

diff --git a/2023/39.pl b/2023/39.pl
new file mode 100755 (executable)
index 0000000..21aa5d7
--- /dev/null
+++ b/2023/39.pl
@@ -0,0 +1,54 @@
+#!/usr/bin/perl -w
+
+use v5.38;
+use List::Util qw(product);
+
+my %types;
+my %dests;
+my %ffs;
+my %inps;
+
+while (<>) {
+       my ($src, @dst) = /\w+/g;
+       ($types{$src}) = /^(\W)/;
+       @{ $dests{$src} } = @dst;
+       $inps{$_}->{$src} = 0 for @dst;
+}
+
+my @sums = (0, 0);
+
+sub snd {
+       my ($q, $name, $pulse) = @_;
+       for (@{ $dests{$name} }) {
+               push @$q, [ $_ , $pulse, $name ];
+               $sums[$pulse]++;
+       }
+}
+
+for (1 .. 1000) {
+       my @q = ([ 'broadcaster', 0, 'button' ]);
+       $sums[0]++;
+       while (@q) {
+               my $p = shift @q;
+               my ($name, $pulse, $origin) = @$p;
+               my $type = $types{$name} // '';
+
+               if ($type eq '%') {
+                       if (!$pulse) {
+                               $ffs{$name} = !$ffs{$name};
+                               snd(\@q, $name, $ffs{$name});
+                       }
+               } elsif ($type eq '&') {
+                       my $in = $inps{$name};
+                       $in->{$origin} = $pulse;
+                       my $out = 1;
+                       $out *= $_ for values %$in;
+                       snd(\@q, $name, !$out);
+               } else {
+                       snd(\@q, $name, 0);
+               }
+       }
+}
+
+say "@sums -> ", product @sums;
+