RedBlack(3pm)						User Contributed Perl Documentation					     RedBlack(3pm)

NAME

       Tree::RedBlack - Perl implementation of Red/Black tree, a type of balanced tree.

SYNOPSIS

	 use Tree::RedBlack;

	 my $t = new Tree::RedBlack;
	 $t->insert(3, 'cat');
	 $t->insert(4, 'dog');
	 my $v = $t->find(4);
	 my $min = $t->min;
	 my $max = $t->max;
	 $t->delete(3);
	 $t->print;

DESCRIPTION

       This is a perl implementation of the Red/Black tree algorithm found in the book "Algorithms", by Cormen, Leiserson & Rivest (more commonly
       known as "CLR" or "The White Book").  A Red/Black tree is a binary tree which remains "balanced"- that is, the longest length from root to
       a node is at most one more than the shortest such length.  It is fairly efficient; no operation takes more than O(lg(n)) time.

       A Tree::RedBlack object supports the following methods:

       new ()
	   Creates a new RedBlack tree object.

       root ()
	   Returns the root node of the tree.  Note that this will either be undef if no nodes have been added to the tree, or a
	   Tree::RedBlack::Node object.  See the Tree::RedBlack::Node manual page for details on the Node object.

       cmp (&)
	   Use this method to set a comparator subroutine.  The tree defaults to lexical comparisons.  This subroutine should be just like a
	   comparator subroutine to sort, except that it doesn't do the $a, $b trick; the two elements to compare will just be the first two items
	   on the stack.

       insert ($;$)
	   Adds a new node to the tree.  The first argument is the key of the node, the second is its value.  If a node with that key already
	   exists, its value is replaced with the given value and the old value is returned.  Otherwise, undef is returned.

       delete ($)
	   The argument should be either a node object to delete or the key of a node object to delete. WARNING!!! THIS STILL HAS BUGS!!!

       find ($)
	   Searches the tree to find the node with the given key.  Returns the value of that node, or undef if a node with that key isn't found.
	   Note, in particular, that you can't tell the difference between finding a node with value undef and not finding a node at all.  If you
	   want to determine if a node with a given key exists, use the node method, below.

       node ($)
	   Searches the tree to find the node with the given key.  Returns that node object if it is found, undef otherwise.  The node object is a
	   Tree::RedBlack::Node object.

       min ()
	   Returns the node with the minimal key.

       max ()
	   Returns the node with the maximal key.

AUTHOR

       Benjamin Holzman <bholzman@earthlink.net>

SEE ALSO

       Tree::RedBlack::Node

perl v5.10.0							    2008-07-31							     RedBlack(3pm)