So far, we have learned about sequential data structures such as arrays (lists), stacks, queues, and linked lists (and their variants). In this chapter, we will cover the data structure called a set.

A set is a collection of items that are unordered and consists of unique elements (meaning they cannot be repeated). This data structure uses the same math concept as of finite sets, but applied to a Computer Science data structure.

Let's take a look at the math concept of sets before we dive into the Computer Science implementation of it. In Mathematics, a set is a collection of distinct objects.

For example, we have a set of natural numbers, which consists of integer numbers greater than or equal to 0: N = {0, 1, 2, 3, 4, 5, 6, …}. The list of the objects within the set is surrounded by {} (curly braces).

There is also the null set concept. A set with no element is called a null set or empty set. For example, a set of prime numbers between 24 and 29. As there is no prime number...