40 Algorithms Every Programmer Should Know

Sets

A set is defined as a collection of elements that can be of different types. The elements are enclosed within { }. For example, have a look at the following code block:

>>> green = {'grass', 'leaves'}>>> print(green){'grass', 'leaves'}

The defining characteristic of a set is that it only stores the distinct value of each element. If we try to add another redundant element, it will ignore that, as illustrated in the following:

>>> green = {'grass', 'leaves','leaves'}>>> print(green){'grass', 'leaves'}

To demonstrate what sort of operations can be done on sets, let's define two sets:

• A set named yellow, which has things that are yellow

• Another set named red, which has things that are red

Note that some things are common between these ...