An array that stores the data pointers based on the calculated index.
typedef struct Entry char *key; char *value; struct Entry *next; // Pointer for collision chaining Entry; typedef struct Dictionary int size; Entry **buckets; // Array of pointers to Entry Dictionary; Use code with caution. Copied to clipboard Choose a Hashing Algorithm
Here is the C code for the dictionary implementation using hashing algorithms:
A good hash function for a string (or integer) key should: c program to implement dictionary using hashing algorithms
A strategy to handle situations where two different keys generate the identical array index. The Problem of Collisions
dict_delete() :
========== DICTIONARY MENU ========== 1. Insert/Update key-value pair 2. Search for a key 3. Delete a key 4. Display all entries 5. Show number of entries 6. Exit Enter your choice: 1 Enter key (string): apple Enter integer value: 5 Inserted ('apple', 5) at index 92 An array that stores the data pointers based
-------------------------------------------------------------*/ unsigned int hash(const char *key, int table_size) unsigned long hash_val = 5381; int c;
In our C implementation, we will treat the key as a (character array) and the value as an integer for simplicity. The same principles apply to any data type – you can easily adapt the code for other types.
Dictionary contents: Bucket 0: (grape -> 8) Bucket 1: Bucket 2: Bucket 3: Bucket 4: (banana -> 7) Bucket 5: Bucket 6: Bucket 7: (apple -> 10) Bucket 8: Bucket 9: (orange -> 3) Delete a key 4
The search function hashes the key and traverses the specific bucket's linked list to find a match.
If we choose m to be roughly proportional to n (i.e., keep α constant, say 0.7–1.0), then α = O(1) , and all operations are (the key length is usually bounded by a constant in practice).
: Each entry requires extra memory for a pointer to the next node.
// Implementations (as shown above)