From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Wed, 3 Dec 2025 05:37:16 +0000 (+0100)
Subject: Day 3: greedy algorithm with regexes
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=14fa074821d260605168260b7f149ea76c32e3f4;p=aoc.git

Day 3: greedy algorithm with regexes
---

diff --git a/2025/05.pl b/2025/05.pl
new file mode 100755
index 0000000..e841b90
--- /dev/null
+++ b/2025/05.pl
@@ -0,0 +1,18 @@
+#!/usr/bin/perl -w
+
+use v5.42;
+
+my $sum;
+ROW:
+while (<>) {
+	for my $x (reverse 1 .. 9) {
+		for my $y (reverse 1 .. 9) {
+			if (/$x.*$y/) {
+				$sum += "$x$y";
+				next ROW;
+			}
+		}
+	}
+}
+
+say $sum;
diff --git a/2025/06.pl b/2025/06.pl
new file mode 100755
index 0000000..f2a5fde
--- /dev/null
+++ b/2025/06.pl
@@ -0,0 +1,20 @@
+#!/usr/bin/perl -w
+
+use v5.42;
+use List::Util qw(sum);
+
+my $len = 12;
+
+sub search {
+	my ($d, $str) = @_;
+	
+	return $str if length $str == $len;
+
+	for my $n (reverse 1 .. 9) {
+		my $re = $n . ('.' x ($len - 1 - length $str));
+		next if $d !~ /$re/;
+		return search($d =~ s/^.*?$n//r, "$str$n");
+	}
+}
+
+say sum map { chomp; search($_, '') } <>;