Hash Table Data Structure

 Hash Table Data Structure

A hash table is a data structure used to store key-value pairs, where the keys are hashed to map to a specific index in an array. It provides constant-time average case performance for insert, delete, and search operations.

python

# Hash Table class

class HashTable:

    def __init__(self, capacity):

        self.capacity = capacity

        self.table = [[] for _ in range(capacity)]

    def hash_function(self, key):

        return hash(key) % self.capacity

    def insert(self, key, value):

        index = self.hash_function(key)

        for item in self.table[index]:

            if item[0] == key:

                item[1] = value

                return

        self.table[index].append((key, value))

    def get(self, key):

        index = self.hash_function(key)

        for item in self.table[index]:

            if item[0] == key:

                return item[1]

        raise KeyError(key)

    def remove(self, key):

        index = self.hash_function(key)

        for i, item in enumerate(self.table[index]):

            if item[0] == key:

                del self.table[index][i]

                return

        raise KeyError(key)