AoC 2017 begins

[aoc.git] / 2017 / 05.pl

diff --git a/2017/05.pl b/2017/05.pl
new file mode 100755 (executable)
index 0000000..f37fa53
--- /dev/null
+++ b/2017/05.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/perl
+
+use v5.30;
+use strict;
+
+my $in = 368078;
+
+my $diam = 0;
+$diam++ while $in > (2*$diam+1)*(2*$diam+1);
+my $dist = 2*$diam-1;
+my $dir = -1;
+my $i = (2*$diam-1)*(2*$diam-1)+1;
+while ($i < $in) {
+       # say "\t$i $dist $dir";
+       if ($dist <= $diam) {
+               $dir = 1;
+       } elsif ($dist > 2*$diam-1) {
+               $dir = -1;
+       }
+       $dist += $dir;
+       $i++;
+}
+
+say $dist;