C Program To Implement Dictionary Using Hashing Algorithms -

Essay: Implementing a Dictionary Using Hashing Algorithms in C

Introduction

In computer science, a dictionary (also known as a symbol table, map, or associative array) is an abstract data type that stores key-value pairs, allowing for efficient insertion, deletion, and retrieval of values based on their unique keys. From compilers managing variable names to databases indexing records, dictionaries are fundamental. Among the various ways to implement a dictionary, hashing stands out as one of the most efficient, offering average-case (O(1)) time complexity for core operations. This essay explores the design and implementation of a dictionary in the C programming language using hashing algorithms, delving into hash functions, collision resolution strategies, and practical coding considerations.

Hang a "Linked List" off Shelf 42. If multiple words land there, just line them up one after another. Hash chose c program to implement dictionary using hashing algorithms

printf("---------------------------\n");

delete_key(dict, "city"); printf("City after deletion: %s\n", search(dict, "city") ?: "Not found");

The following example uses a simple hash function and separate chaining to handle collisions. Essay: Implementing a Dictionary Using Hashing Algorithms in

3. Dictionary Operations

Initialization

HashTable* create_dict(int size) 
    HashTable *dict = (HashTable*)malloc(sizeof(HashTable));
    if (!dict) return NULL;
dict->size = size;
dict->count = 0;
dict->buckets = (Entry**)calloc(size, sizeof(Entry*));
return dict;

if (found) *found = 0;
return -1;

#include #include #include #define SIZE 20 struct DataItem char key[50]; char value[100]; ; struct DataItem* hashArray[SIZE]; // Simple hash function (Sum of ASCII values % SIZE) int hashCode(char* key) int hash = 0; for(int i = 0; key[i] != '\0'; i++) hash += key[i]; return hash % SIZE; // Insert a word and definition void insert(char* key, char* value) struct DataItem* item = (struct DataItem*) malloc(sizeof(struct DataItem)); strcpy(item->key, key); strcpy(item->value, value); int hashIndex = hashCode(key); // Linear Probing: find next empty slot while(hashArray[hashIndex] != NULL) hashIndex = (hashIndex + 1) % SIZE; hashArray[hashIndex] = item; // Search for a definition char* search(char* key) int hashIndex = hashCode(key); while(hashArray[hashIndex] != NULL) if(strcmp(hashArray[hashIndex]->key, key) == 0) return hashArray[hashIndex]->value; hashIndex = (hashIndex + 1) % SIZE; return "Not Found"; int main() insert("Algorithm", "A step-by-step procedure for calculations."); insert("Pointer", "A variable that stores a memory address."); insert("Boolean", "A data type with two possible values: true or false."); printf("Search 'Pointer': %s\n", search("Pointer")); printf("Search 'C-Language': %s\n", search("C-Language")); return 0; Use code with caution. Copied to clipboard Why this works Speed: In a perfect scenario, finding a word is if (found) *found = 0; return -1;