What is the difference between a hash table and a set?

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What is the difference between a hash table and a set?

A hash table and a set are both data structures used to store and retrieve elements efficiently. However, there are some key differences between the two.

A hash table, also known as a hash map, is a data structure that uses a hash function to map keys to values. It allows for efficient insertion, deletion, and retrieval of elements based on their keys. In a hash table, each key is unique, and the values associated with the keys can be accessed and modified. The hash function is used to compute an index or a bucket where the key-value pair is stored, allowing for constant-time operations on average.

On the other hand, a set is a data structure that stores a collection of unique elements. Unlike a hash table, a set does not associate any values with the elements. It is primarily used to check for the presence or absence of an element in the set. Sets typically support operations like insertion, deletion, and membership testing in constant time on average.

In summary, the main difference between a hash table and a set lies in their purpose and functionality. A hash table is used to store key-value pairs, allowing for efficient retrieval and modification of values based on their keys. A set, on the other hand, is used to store a collection of unique elements and primarily supports operations related to element presence or absence.