]> www.fi.muni.cz Git - aoc.git/blobdiff - 2020/19.pl
Moved 2020 to a subdir
[aoc.git] / 2020 / 19.pl
diff --git a/2020/19.pl b/2020/19.pl
new file mode 100755 (executable)
index 0000000..c9f7f39
--- /dev/null
@@ -0,0 +1,16 @@
+#!/usr/bin/perl -w
+
+use strict;
+
+local $/;
+my @ads = sort { $a <=> $b } map { chomp; $_ } split /\n/, <>;
+
+my $prev = 0;
+my %diffs;
+for my $n (@ads) {
+       $diffs{ $n - $prev }++;
+       $prev = $n;
+}
+$diffs{3}++;
+
+print $diffs{1} * $diffs{3}, "\n";