(List and Queues without Tail Pointers) Our implementation of a linked list (Figs. 19.4–19...

(List and Queues without Tail Pointers) Our implementation of a linked list (Figs. 19.4–19.5) used both a firstPtr and a lastPtr. The lastPtr was useful for the insertAtBack and removeFromBack member functions of the List class. The insertAtBack function corresponds to the enqueue member function of the Queue class. Rewrite the List class so that it does not use a lastPtr. Thus, any operations on the tail of a list must begin searching the list from the front. Does this affect our implementation of the Queue class (Fig. 19.16)?

Fig.19.4 ListNode class-template definition.

Fig.19.5 List class-template definition. (Part 1 of 4.)

Fig.19.5 List class-template definition. (Part 2 of 4.)

Fig. 19.5 List class-template definition. (Part 3 of 4.)

Fig. 19.5 List class-template definition. (Part 4 of 4.)

Fig. 19.16 Queue class-template definition. (Part 1 of 2.)

Fig.19.16 Queue class-template definition. (Part 2 of 2.)