C Program To Implement Dictionary Using Hashing Algorithms |link| Guide
prev = curr; curr = curr->next;
// Cleanup destroy_hash_table(dict);
A mechanism to handle situations where two different keys produce the same hash index. Because the array size is finite and the number of possible keys is infinite, collisions are inevitable. 2. Choosing a Collision Resolution Strategy
unsigned long hash_fnv1a(const char *str, int table_size) unsigned long hash = 2166136261UL; int c; while ((c = *str++)) hash ^= c; hash *= 16777619; c program to implement dictionary using hashing algorithms
// [Include all the functions defined above: hash_djb2, create_hash_table, // insert, search, delete_key, display, destroy_hash_table]
printf("\n");
// Print the hash table void printHashTable(HashTable* hashTable) for (int i = 0; i < HASH_TABLE_SIZE; i++) Node* current = hashTable->buckets[i]; printf("Bucket %d: ", i); while (current != NULL) printf("%s -> %s, ", current->key, current->value); current = current->next; prev = curr; curr = curr->next; // Cleanup
// Delete a key printf("\nDeleting 'orange'...\n"); if (delete_key(dict, "orange")) printf("'orange' deleted successfully.\n"); else printf("'orange' not found.\n");
First, define the linked list node for the chain:
We use an array of linked lists (buckets). Each bucket contains all key-value pairs that hash to the same index. This method is simple, handles an arbitrary number of collisions gracefully, and does not require the table to be resized as aggressively as open addressing. Using a hashing algorithm is the most efficient
Using a hashing algorithm is the most efficient way to build a dictionary. It maps keys to specific indices in an array, offering average-case time complexities of for lookup, insertion, and deletion. 1. Core Concepts of Hashing
Always free memory to avoid leaks.
The same key must always produce the same hash index.
These functions handle the logic of finding the right "bucket" and managing the linked list.
Instead of using static buffers, this implementation calls strdup() . This function dynamically allocates exactly enough bytes on the heap to house the strings. It prevents buffer overflows and conserves memory. 2. The Mechanics of the Hash Function