Lecture 16: Tree Traversal

Introduction

Tree Traversals abejknopfcdglmhi jenkopbfaclgmdhi jhopkefbclmghida PREORDER INORDER POSTORDER

Tree Traversal Algorithms Ordered tree traversals are based on the depth-first graph traversal. The structure of all depth-first tree traversals are the same. The diffence is in when each node is evaluated. function traverse(node: X) { for (all child nodes Y) traverse(Y) }

Permutation Tree for Four Elements

Simple Maze Solving as Tree Traversal

List Representation of a Binary Tree

Edge List Representations of a Tree

Dynamic Memory Representations of a Tree

A General Tree in Dynamic Memory

Data-Tag-Next

Example: Breadth-First Traversal

Breadth-First Traversal of a Tree sample Ada Code

Depth-First Traversal - Binary Dreet

Depth-First Traversal of a Tree

Implementing Depth-First Traversals PREORDER INORDER POSTORDER

Watching the Stack

Summary DFT Tree Traversals Pre-order In-order Post-order Permutation Trees Simple Maze as a Tree List Representation of a Binary Tree Edge List Representation of a Tree Trees in Dynamic Memory Data-Tag-Next: a general tree node Breadth-First Traversals Usually on Permutation Trees Iterative with a Queue Depth-First Traverals Used mostly for search and sort Recursive with a Stack