AoC 2017 begins

[aoc.git] / 2017 / 17.pl

diff --git a/2017/17.pl b/2017/17.pl
new file mode 100755 (executable)
index 0000000..1a1f1a6
--- /dev/null
+++ b/2017/17.pl
@@ -0,0 +1,21 @@
+#!/usr/bin/perl
+
+use v5.30;
+use strict;
+
+chomp (my $stream = <>);
+
+1 while $stream =~ s/<[^!>]*!./</;
+1 while $stream =~ s/<[^>]*?>//;
+
+my $sum;
+my $depth = 0;
+for my $c (split //, $stream) {
+       if ($c eq '{') {
+               $depth++;
+       } elsif ($c eq '}') {
+               $sum += $depth--;
+       }
+}
+
+say $sum;