Introduction to Trees

Learning Objectives Define a tree data structure and its key components. Identify the root, parent, child, and leaf nodes in a given tree diagram. Explain the hierarchical relationship between nodes. Differentiate between a tree and other data structures like a list. Draw a simple tree structure based on a set of relationships. Describe at least two real-world examples of tree structures. Have you ever wondered how your computer organizes all your files and folders? 📂 It's not a simple list; it's a powerful structure called a tree! In this lesson, we'll explore the tree data structure, a fundamental concept in computer science. You'll learn the special vocabulary used to describe trees and understand why they are so useful for organizing information hie...

TermDefinitionExample TreeA data structure that simulates a hierarchy, like a tree in nature but upside down. It consists of nodes connected by edges.A school's organization chart, with the Principal at the top, then Vice-Principals, then Department Heads, and finally Teachers. NodeA single point or element in a tree that holds data. Think of it as a person in a family tree or a folder in a file system.In a file system tree, the 'Documents' folder is a node. RootThe topmost node in a tree, from which all other nodes descend. A tree has only one root.In a file system, the 'C:' drive is the root node. Parent and ChildA node that has nodes directly below it is a 'parent'. The nodes directly below it are its 'children'.If a 'Photos' folde...

The Single Root Rule A tree must have exactly one root node. This rule ensures there is a single starting point for the entire structure. If there were two roots, it would be two separate trees (a 'forest'). The Parent-Child Connection Rule Every node (except the root) has exactly one parent. This rule prevents loops and ensures a clear hierarchy. A child cannot have two parents, which is what makes a tree different from more complex graph structures. The No-Cycles Rule You can never follow edges from a node and end up back at the same node. This means you can't have a child node that is also its own parent or grandparent. The path always goes one way: down from the root.