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Sep 15, 2023
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Understanding Hashing Tables and Hashing Tables
Hashing and its tables are essential concepts in computer science, data structures and other applications. They can be used to store, retrieve and manage data efficiently, providing fast access to information. This article explores the principles, applications and benefits of hashing, as well as hash tables. Data Structures and Algorithms With Python Course in Pune
Hashing - A Basic Concept
Hashing is the process of transforming data with arbitrary sizes into a fixed value. This value is usually a numerical code called a hashcode or hashvalue. Hashing's primary goal is to map data into a fixed-size area, usually a specific index within an array. This is done in a deterministic, efficient manner. Hash codes are unique and can be generated for each input. However, collisions may occur when the hash codes of two inputs match.
Hash Functions
The hash function is at the heart of hashing. It takes an input or 'key' and generates a hashcode. A good hash code should meet several criteria:
Deterministic : The hash function must consistently produce the same code for the same input.
Efficient should calculate the hash code quickly.
Uniform distribution: In order to reduce collisions, it is ideal that hash values are distributed uniformly across all possible hash codes.
Avalanche effect: A slight change in input should produce a hash code that is significantly different.
Preimage Resistance : It should not be possible to reverse the process, and find the original input by its hash code.
Hash functions can be used for a wide range of applications including cryptography, data retrieval and data integrity checks. Hash functions are popular in cryptography applications.
Practice of Hash Codes
In practice, hash codes are used widely. Hash codes are used in hash tables to enable fast data retrieval. Hash codes can be used to locate data quickly within a structure similar to an array. They provide constant-time complexity for insertions, deletions, and retrieval. Hashing is also used in data storage, password storage and data retrieval.
Hash Tables: Efficient Data Storage
Hash tables, or hash maps, are data structures that use hashing as a way to store and retrieve information efficiently. It is made up of an array "buckets", or "slots" that can each hold data (key-value pair). The hash code is generated by a key and used to determine which bucket the data should go into or be retrieved from. Data Structures and Algorithms With Python Classes in Pune
Hash Table Operation
Hash tables are used for three basic operations.
