Data Structures and Algorithms with JavaScript

Chapter 10. Binary Trees and Binary Search Trees

Trees are a commonly used data structure in computer science. A tree is a nonlinear data structure that is used to store data in a hierarchical manner. Tree data structures are used to store hierarchical data, such as the files in a file system, and for storing sorted lists of data. We examine one particular tree structure in this chapter: the binary tree. Binary trees are chosen over other more primary data structures because you can search a binary tree very quickly (as opposed to a linked list, for example) and you can quickly insert and delete data from a binary tree (as opposed to an array).

Trees Defined

A tree is made up of a set of nodes connected by edges. An example of a tree is a company’s organizational chart (see Figure 10-1).

The purpose of an organizational chart is to communicate the structure of an organization. In Figure 10-1, each box is a node, and the lines connecting the boxes are the edges. The nodes represent the positions that make up an organization, and the edges represent the relationships between those positions. For example, the CIO reports directly to the CEO, so there is an edge between those two nodes. The development manager reports to the CIO, so there is an edge connecting those two positions. The VP of Sales and the development manager do not have a direct edge connecting them, so there is not a direct relationship between those two positions.

Figure 10-1. An organizational chart is a tree ...