From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Wed, 25 Dec 2024 05:13:33 +0000 (+0100)
Subject: Day 25: keys and locks
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=72dc84c2b22c8b780083e281569d5b93b4a6543e;p=aoc.git

Day 25: keys and locks
---

diff --git a/2024/49.pl b/2024/49.pl
new file mode 100755
index 0000000..ef8069a
--- /dev/null
+++ b/2024/49.pl
@@ -0,0 +1,19 @@
+#!/usr/bin/perl -w
+
+use v5.40;
+
+$/ = "\n\n";
+my @keys = <>;
+
+my $pairs;
+for my ($i, $k1) (indexed @keys) {
+	K2:
+	for my $k2 (@keys[$i+1 .. $#keys]) {
+		for my $i (0 .. length $k1) {
+			next K2 if substr($k1, $i, 1) eq '#'
+				&& substr($k2, $i, 1) eq '#';
+		}
+		$pairs++;
+	}
+}
+say $pairs;