C$++$ recursively implement the following with a$.)$ a linear linked list, b$.)$ a doubly linked list, and c$.)$ a circulalrlinked list. All implementations must include both a public wrapper function

and a private recursive function. Include any additional functions you need but solve the problem in the least amout of traversals possible. Do NOT use loops or void$/$node return types $($int or bool only$).$

Supplied code includes class list and:

struct node $\{$

int data;

node $*$ next; $//$if linear LL

node $*$ previous; $//$if doubly LL

node $*$ rear; $//$if circular LL

Make a copy of every other node from one list into a new list.

Do not copy over any duplicate values. Return the average of

all the values in the new copied list.