Doubly-linked list/Element definition
Doubly-linked list/Element definition
You are encouraged to solve this task according to the task description, using any language you may know.
You are encouraged to solve this task according to the task description, using any language you may know.
Define the data structure for a doubly-linked list element. The element should include a data member to hold its value and pointers to both the next element in the list and the previous element in the list. The pointers should be mutable.
Ada
type Link; type Link_Access is access Link; type Link is record Next : Link_Access := null; Prev : Link_Access := null; Data : Integer; end record;
C
struct link { struct * link next; struct * link prev; int data; };
Perl
Just use an array. You can traverse and splice it any way. Linked lists are way too low level.
However, if all you got is a algorithm in a foreign language, you can use references to accomplish the translation.
my %node = ( data => 'say what', next => \%foo_node, prev => \%bar_node, ); $node{next} = \%quux_node; # mutable
Pop11
uses objectclass; define :class Link; slot next = []; slot prev = []; slot data = []; enddefine;
Ruby
class ListNode attr_accessor :val, :nxt, :prv def initialize(mval,mprv=nil,mnxt=nil) self.val=mval self.prv=mprv self.nxt=mnxt end def each(&b) yield val nxt.each(&b) if nxt self end include Enumerable end