Day 25: shortened version

diff --git a/2024/49.pl b/2024/49.pl
index ef8069ad0637de966be7ba5181f7d35d419a7461..54bdc463a312586a089baf720eae92481811ee8c 100755 (executable)
--- a/2024/49.pl
+++ b/2024/49.pl
@@ -3,17 +3,17 @@
 use v5.40;
 
 $/ = "\n\n";
-my @keys = <>;
-
+my @keys;
 my $pairs;
-for my ($i, $k1) (indexed @keys) {
+while (<>) {
        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 '#';
+       for my $k (@keys) {
+               for my $i (0 .. length) {
+                       next K2 if substr($_, $i, 1) eq '#'
+                               && substr($k, $i, 1) eq '#';
                }
                $pairs++;
        }
+       push @keys, $_;
 }
 say $pairs;