Program in C++ please

Here the doubly list http://www.sanfoundry.com/cpp-program-implement-doubly-linked-list/

4. (20 points) Consider a double-linked linked list implementation with the following node: struct Node int data; Node *prev; Node next; Write a copy List method that is not a member of any class. The method should take a head pointer and return another pointer. Do not modify the input