1. What advantage does a circular linked structure with a dummy header node give the programmer? 2 Describe one benefit and one cost of a doubly linked structure, as compared to a singly linked...

1. What advantage does a circular linked structure with a dummy header node give the programmer? 2 Describe one benefit and one cost of a doubly linked structure, as compared to a singly linked structure.

3. Examples of linear collections are

a sets and trees

b lists and stacks

4. Examples of unordered collections are

a queues and lists

b sets and dictionaries

5 .A hierarchical collection can represent a

a line of customers at a bank

b a file directory system