Solve day 05, in Perl.

2017/README.md

@@ -18,7 +18,7 @@ The current plan, in no particular order:
 - [ ] Kotlin
 - [ ] Node.js
 - [ ] Objective C
-- [ ] Perl
+- [x] Perl - [Day 05](./day-05/solution.pl)
 - [ ] PHP
 - [ ] Prolog
 - [ ] Python

2017/day-05/solution.pl

@@ -0,0 +1,38 @@
+#!/usr/bin/perl
+my @instructions;
+
+for $line ( <STDIN> ) {
+	push @instructions, $line;
+}
+
+@instructions2 = @instructions;
+
+$iptr = 0;
+
+$steps = 0;
+
+while ($iptr >= 0 and $iptr < 0 + @instructions) {
+	$jump = @instructions[$iptr];
+	@instructions[$iptr]++;
+	$steps++;
+
+	$iptr += $jump
+}
+
+print $steps, "\n";
+
+$iptr = 0;
+$steps = 0;
+
+while ($iptr >= 0 and $iptr < 0 + @instructions2) {
+	$jump = @instructions2[$iptr];
+	if ($jump >= 3) {
+		@instructions2[$iptr]--;
+	} else {
+		@instructions2[$iptr]++;
+	}
+	$steps++;
+
+	$iptr += $jump
+}
+print $steps, "\n";