Mastering Algorithms with C

An Introduction to Data Structures

Data comes in all shapes and sizes, but often it can be organized in the same way. For example, consider a list of things to do, a list of ingredients in a recipe, or a reading list for a class. Although each contains a different type of data, they all contain data organized in a similar way: a list. A list is one simple example of a data structure. Of course, there are many other common ways to organize data as well. In computing, some of the most common organizations are linked lists, stacks, queues, sets, hash tables, trees, heaps, priority queues, and graphs, all of which are discussed in this book. Three reasons for using data structures are efficiency, abstraction, and reusability.

Efficiency

Data structures organize data in ways that make algorithms more efficient. For example, consider some of the ways we can organize data for searching it. One simplistic approach is to place the data in an array and search the data by traversing element by element until the desired element is found. However, this method is inefficient because in many cases we end up traversing every element. By using another type of data structure, such as a hash table (see Chapter 8) or a binary tree (see Chapter 9) we can search the data considerably faster.

Abstraction

Data structures provide a more understandable way to look at data; thus, they offer a level of abstraction in solving problems. For example, by storing data in a stack (see Chapter 6), we can focus on things ...