C++ Data Structures : Please explain it in detail by adding comments (All the answers to the same question posted on chegg looks confusing for me please help)

4. Write a client function that merges two instances of the Sorted List ADT using the following specification. MergeLists(SortedType list1, SortedType list2, SortedType& result)

Function: Merge two sorted lists into a third sorted list.

Preconditions: list1 and list2 have been initialized and are sorted by key using function ComparedTo. list1 and list2 do not have any keys in common.

Postconditions: result is a sorted list that contains all of the items from list1 and list2.

a. Write the prototype for MergeLists.

b. Write the function definition, using an array-based implementation.

c. Write the function definition, using a linked implementation.

d. Describe the algorithm in terms of Big-O.

5. Rewrite Exercise 4, making MergeLists an array-based member function of the Sorted List ADT.

6. Rewrite Exercise 5, making MergeLists a linked member function of the Sorted List ADT.