From 72dc84c2b22c8b780083e281569d5b93b4a6543e Mon Sep 17 00:00:00 2001
From: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Date: Wed, 25 Dec 2024 06:13:33 +0100
Subject: [PATCH] Day 25: keys and locks

---
 2024/49.pl | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100755 2024/49.pl

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;
-- 
2.43.5