Data Structures
	• Doubly Linked list...      private:   (each node has a node * prev)        node * head;        node * tail;  //???helpful? • Again, there is nothing in a stack that will benefit from each node having a pointer to the previous node. • Using a doubly linked list to allow the “top” to be at the “end” or tail position, this is a poor choice...wastes memory and adds additional operations...