midorder

Midorder is a term that appears occasionally in discussions of tree traversal and algorithms, but it does not have a single, universally accepted definition. In contrast to well-established orders such as preorder, inorder, and postorder, midorder is not part of formal curricula or standard libraries, and its meaning is defined variably by authors and papers.

The most common interpretation in online discussions is that midorder is a synonym for inorder traversal, i.e., left subtree, then node, then right subtree (LNR). Under this reading, the visitation sequence produced by midorder is identical to that of inorder on binary trees, and it preserves the sorted-order property for binary search trees.

Other usages treat midorder as a nonstandard or context-dependent variant in which the root is visited between the left and right subtrees, or as a traversal that emphasizes the middle region of a tree or sequence. Because such definitions are not standardized, they can differ between sources and may not be compatible with each other.

In practice, when encountering the term midorder, it is advisable to consult the specific source for its definition. Absent a stated convention, one should avoid assuming a fixed meaning and prefer using the widely adopted terms: preorder, inorder, or postorder for clarity.

See also: Tree traversal, Inorder traversal, Preorder traversal, Postorder traversal.