Implement the Stack and Queue interfaces with a unique class that is derived from class LinkedDeque typedef string Elem; // deque element type class LinkedDeque { // deque as doubly linked list public: LinkedDeque(); // constructor int size() const; // number of items in the deque bool empty() const; // is the deque empty? const Elem& front() const throw(DequeEmpty); // the first element const Elem& back() const throw(DequeEmpty); // the last element void insertFront(const Elem& e); // insert new first element void insertBack(const Elem& e); // insert new last element void removeFront() throw(DequeEmpty); // remove first element void removeBack() throw(DequeEmpty); // remove last element private: // member data DLinkedList D; // linked list of elements int n; // number of elements };