Year 2015

[aoc.git] / 2015 / 13.pl

diff --git a/2015/13.pl b/2015/13.pl
new file mode 100755 (executable)
index 0000000..4f78ed0
--- /dev/null
+++ b/2015/13.pl
@@ -0,0 +1,35 @@
+#!/usr/bin/perl -w
+
+use v5.16;
+use strict;
+use feature 'bitwise';
+
+$/ = undef;
+$_ = <> . "\n";
+
+while (1) {
+       my ($wire, $val);
+       if (s/^(\d+) -> (\w+)\n//m) {
+               ($wire, $val) = ($2, $1);
+       } elsif (s/^NOT (\d+) -> (\w+)\n//m) {
+               ($wire, $val) = ($2, $1 ^ 0xFFFF);
+       } elsif (s/^(\d+) AND (\d+) -> (\w+)\n//m) {
+               ($wire, $val) = ($3, $1 & $2);
+       } elsif (s/^(\d+) OR (\d+) -> (\w+)\n//m) {
+               ($wire, $val) = ($3, $1 | $2);
+       } elsif (s/^(\d+) RSHIFT (\d+) -> (\w+)\n//m) {
+               ($wire, $val) = ($3, $1 >> $2);
+       } elsif (s/^(\d+) LSHIFT (\d+) -> (\w+)\n//m) {
+               ($wire, $val) = ($3, ($1 << $2) & 0xFFFF);
+       }
+       last if !$wire;
+       if ($wire eq 'a') {
+               say "a=$val";
+               last;
+       }
+       # say "$wire => $val";
+       last if $val !~ /\A\d+\z/;
+       $val &= 0xFFFF;
+       s/\b$wire\b/$val/g;
+       # say "$_\n\n";
+}