C Program To Implement Dictionary Using Hashing Algorithms Better — Secure

printf("NULL\n");

One of the most efficient ways to implement a dictionary is through . Hashing uses a hash function to map a key directly to the location where its corresponding value is stored. When implemented correctly, hashing yields average constant time ( O(1) ) for the basic operations, making it exceptionally fast.

#define TABLE_SIZE 10007 // A prime number for better distribution

: An array that stores pointers to key-value pairs. c program to implement dictionary using hashing algorithms

To implement a dictionary in C using hashing, you essentially build a that maps string keys to specific values . Since C lacks a built-in dictionary type, you must manage memory and collisions manually. 1. Core Components

For multithreaded programs, add mutex locks per bucket (fine-grained locking) or a single global lock (coarse-grained but simpler):

prev = current; current = current->next; printf("NULL\n"); One of the most efficient ways to

dict_search() uses the hash to locate the correct list, then walks the list comparing keys with strcmp . If a match is found, it writes the value to the output parameter *val and returns 1 (true). Otherwise, returns 0.

// The hash table structure typedef struct KeyValuePair **buckets; // Array of pointers to linked list heads int size; // Current number of buckets (table size) int count; // Total number of key-value pairs stored HashTable;

free(curr->key); free(curr); d->count--; printf("Deleted key '%s'\n", key); return 1; #define TABLE_SIZE 10007 // A prime number for

In the realm of computer science, a dictionary (also known as a map, symbol table, or associative array) is one of the most fundamental and versatile data structures. It allows you to store key-value pairs and retrieve values in near-constant time, regardless of the size of the data. While languages like Python, Java, and C++ have built-in dictionary implementations (e.g., dict , HashMap , std::unordered_map ), the C programming language does not provide a standard one. This forces C developers to implement their own dictionary from scratch.

: An algorithm to convert a string key into a numerical array index.

// djb2 Hash Function unsigned long hash(const char *str) unsigned long hash = 5381; int c; while ((c = *str++)) hash = ((hash << 5) + hash) + c; // hash * 33 + c return hash % TABLE_SIZE;

// The hash table – an array of pointers to Entry typedef struct Dictionary Entry **buckets; int size; // number of buckets (table_size) int count; // number of stored entries Dictionary;