preorder — English Dictionary

Verb

1. To order (goods or services) in advance, before they are available.

   Usage

   • Intransitive
   • Transitive

   Examples

   Preorder now at website.com!

2. To sort or arrange beforehand.

   Usage

   • Transitive

Noun

1. An order for goods or services placed in advance.

   Examples

   available for preorder

   Head over to website.com and get your preorder in.

2. A binary relation that is reflexive and transitive.

   Examples

   The relation of logical implication over sentences is an example of a preorder.

   Example 436 For each set A, the relation #92;subseteq is a preorder on #92;mathcal#123;P#125;(A).

   More examples (2)

   Let us first compare S#95;1, S#95;2 and S#95;3 w.r.t. the partial preorder #92;succeq.

   2000, Jean-Charles Pomerol, Sergio Barba-Romero, Multicriterion Decision in Management: Principles and Practice, Springer, Softcover, page 58, It can easily be verified that the above relation is a preorder, i.e. that it is reflexive and transitive.

Adjective

1. Such that, recursively, the root is visited before the left and right subtrees.

   Usage

   • not-comparable
   • of a traversal of a tree

   Broader terms

   depth-first

   Examples

   Now, the preorder traversal of a tree can be constructed from the preorder traversals of the subtrees rooted at the children of the root of the tree.

   In the program given above, tree is constructed and is traversed in inorder, preorder and postorder traversal.

   More examples (1)

   2011, Ananda Rao Akepogu, Radhika Raju Palagiri, Data Structures and Algorithms Using C++, Pearson Education India, page 9.16, The preorder traversal visits a node first after which it traverses its left subtree and then traverses its right subtree.