Write a program that merges two sorted linked lists to form a single sorted linked list.  To solve this problem, write a program that performs the following steps:

 1.Declare an array of 20 spaces, and randomly assign 20 integers between 1 and 1000.

 2. Sort this array in ascending order by selection sort.

3. Organize the contents of the sorted array into a sorted linked list (the linked list variable is a), and print each node of the list in order.

 4. Construct a linked list b, and print each node in the list in order (repeat steps 1, 2, 3).

 5. Merge the linked lists of a and b to form 40 linked lists d sorted into one, and print each node of the list d in order.