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

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

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;

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 the Tree::RedBlack::Node manpage 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.

Benjamin Holzman <bholzman@earthlink.net>

Tree::RedBlack::Node

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