3. (20 pts) Consider a doubly linked list of items that are in no particular order. Assume the doubly linked list has only a head reference. You are allowed to use only one temporary curr reference without the need of others such as prev. a. Write instructions to insert a node referenced by newNode at the beginning of the linked list. b. Write instructions to delete a node referenced by newNode at the beginning of the linked list. C. Write instructions to insert a node referenced by newNode at the end of the linked list. d. Write instructions to delete a node referenced by newNode at the end of the linked list. Similar to Problem 1, you should consider special cases