Reaching the Last Song, and Going Back One: Doubly Linked Lists

A linked list knows its first song, but "Add to queue" needs the last one and the Previous button needs the one before. Make both one step, and add and remove anywhere you already are by changing a couple of references.

Updated

Cheat sheet: Reaching the Last Song, and Going Back One: Doubly Linked Lists
Category
Data Structures
Level
Apprentice
Tags
data structures, Doubly Linked List, Head and Tail (data-structures), Linked List