Added Perl.

README.md

@@ -7,6 +7,7 @@ Currently DoublesGame exists in the following languages:
  - C
  - C++
  - Java
+ - Perl
  - Python
 
 Building

src/doublesgame.pl

@@ -0,0 +1,39 @@
+# Copyright (C) 2017 Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net> All rights reserved.
+# Author: Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+#
+# This software is provided 'as-is', without any express or implied
+# warranty. In no event will the authors be held liable for any damages
+# arising from the use of this software.
+#
+# Permission is granted to anyone to use this software for any purpose,
+# including commercial applications, and to alter it and redistribute it
+# freely, subject to the following restrictions:
+#
+# 1. The origin of this software must not be misrepresented; you must not
+#    claim that you wrote the original software. If you use this software
+#    in a product, an acknowledgment in the product documentation would be
+#    appreciated but is not required.
+#
+# 2. Altered source versions must be plainly marked as such, and must not be
+#    misrepresented as being the original software.
+#
+# 3. This notice may not be removed or altered from any source
+#    distribution.
+
+$n = 1;
+
+$run = 1;
+
+while($run == 1) {
+	print "2^$n=";
+	$a = <>;
+	if($a == 0) {
+		print "Goodbye!\n";
+		$run = 0;
+	} elsif($a != 1 << $n) {
+		print "Wrong answer, try again.\n";
+	} else {
+		print "Correct!\n";
+		++$n;
+	}
+}