Moved 2021 to a subdir

[aoc.git] / 2021 / 05.pl

diff --git a/2021/05.pl b/2021/05.pl
new file mode 100755 (executable)
index 0000000..7fd647b
--- /dev/null
+++ b/2021/05.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/perl -w
+
+use v5.16;
+
+my ($c, @s);
+
+while (<>) {
+       $c++;
+       chomp;
+       my $i = 0;
+       for my $b (split//) {
+               $s[$i++] += $b;
+       }
+}
+
+my ($e, $g);
+for my $b (@s) {
+       $e .= ($b > $c/2) ? '1' : '0';
+       $g .= ($b > $c/2) ? '0' : '1';
+}
+
+say oct("0b$e")*oct("0b$g");
+