Hashing

Hashing is a fundamental concept in computer science used to efficiently store and retrieve data in a data structure called a hash table. The idea behind hashing is to map data elements to specific locations in the hash table based on their keys.

Following are the components of Hashing:

Working:

Hash Function: A hash function takes an input (usually a key) and returns a fixed-size string of characters, which is typically a hash code. The output of a hash function is called a hash value or hash code. A good hash function should distribute the keys uniformly across the hash table, reducing the chances of collisions (more on this later).

Hash Table: A hash table is an array of fixed size where each element is called a bucket or slot. Each bucket can store one or more key-value pairs. The hash table provides constant-time (O(1)) access to elements based on their keys.

Insertion: When inserting a new key-value pair into the hash table, the hash function is applied to the key to compute the hash code. The hash code determines the index or position where the key-value pair will be stored in the hash table.

Retrieval: To retrieve the value associated with a key, the hash function is again applied to the key to compute its hash code. The hash code is then used to locate the corresponding bucket in the hash table, where the value is stored.