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Annotated edit history of LinkedList version 6, including all changes. View license author blame.
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1 SamJansen 1 A data structure used in programming to allow dynamic length lists allowing quick iteration, addition and subtraction from the list. Random access is not quick, however, requiring a search of the list. There are a few variants of [LinkedList]s: singly-linked lists, doubly-linked lists and circular lists (which can be either singly or doubly linked).
2
3 A simple singly linked list in C++:
4
5 template<class T>
6 struct !LinkedListNode
7 {
8 T data;
9 !LinkedListNode *next;
10 };
11
4 GlynWebster 12 [LinkedList]s work by each node merely pointing to the next node in the list, where the last node has a NullPointer. Doubly-linked lists have a previous pointer as well, allowing bi-directional iteration. A circular list has the last node pointing back to the first node. Adding and deleting nodes aren't terribly complex but require a little thinking; you need to store temporary pointers and do a little magic.
3 GlynWebster 13
6 AristotlePagaltzis 14 Most higher level languages have linked list constructs. For example [C++] has the [STL], [Java] has a LinkedList in its class libraries. Category:FunctionalProgrammingLanguages almost always have linked lists as built-in datatypes, the linked list is the primary datatype in [LISP]. If you are coding [C], however, you might have to write your own.
3 GlynWebster 15
16 ''Note'': Python has a "list" datatype, but it is implemented as an array of pointers, so don't treat it like a linked list -- prepending elements to the head of a Python list one by one is not an efficent thing to do.