day2

day2.pl

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+use Data::Dumper;
+
+my $file = "input2.txt";
+
+open(my $f, '<', $file) or die "cannot open file";
+
+my $fh = <$f>;
+my @ranges = split(/,/, $fh);
+
+my $totalPhony = 0;
+foreach my $range (@ranges) {
+    $totalPhony += getPhonyPins(split(/-/, $range));
+}
+
+print "Total phony: $totalPhony\n";
+
+
+sub getPhonyPins {
+
+    ($startInt, $endInt) = @_;
+
+    my $totalphony = 0;
+    my $found = 0;
+
+    NEXT: foreach my $i ($startInt .. $endInt) {
+        my @digits = split (//, $i);
+        # check for odd digits (cant have pairs)
+        my $digits = @digits;
+        if ($digits % 2 == 1) {
+            next;
+        }
+
+        for (my $len = 1; $len <= $digits/2; $len++) {
+            next unless $digits % $len == 0; # only use divisors
+
+            my $pattern = substr($i, 0, $len);
+            my $expected = $pattern x ($digits / $len);
+            if ($i eq $expected) {
+                $totalphony += $i;
+                $found += 1;
+                next NEXT;
+            }
+        }
+    }
+
+    print "Found: $found ($totalphony indv) for ($startInt, $endInt)\n";
+    return $totalphony;
+}

input2.txt

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+9191906840-9191941337,7671-13230,2669677096-2669816099,2-12,229599-392092,48403409-48523311,96763-229430,1919163519-1919240770,74928-96389,638049-668065,34781-73835,736781-819688,831765539-831907263,5615884-5749554,14101091-14196519,7134383-7169141,413340-625418,849755289-849920418,7745350-7815119,16717-26267,4396832-4549887,87161544-87241541,4747436629-4747494891,335-549,867623-929630,53-77,1414-3089,940604-1043283,3444659-3500714,3629-7368,79-129,5488908-5597446,97922755-98097602,182-281,8336644992-8336729448,24-47,613-1077