adding cs142 code

cs142/lab10/Factory.h

@@ -0,0 +1,21 @@
+#pragma once
+#include "ArenaInterface.h"
+/*
+	WARNING: It is expressly forbidden to modify any part of this document, including its name
+*/
+//=======================================================================================
+/*
+	createArena()
+
+	Creates and returns an object whose class extends ArenaInterface.
+	This should be an object of a class you have created.
+
+	Example: If you made a class called "Arena", you might say, "return new Arena();".
+*/
+class Factory
+{
+public:
+	static ArenaInterface* createArena();
+};
+
+//=======================================================================================