how can i create a dynamic array of a hash table in c

Question

i have the following bucket entry structure and hash table set up

typedef struct Hash_Entry
{
    struct Hash_Entry *next;    
    void        *key_Data;  
    unsigned    key_hash;   
    char        key[5]; 
} Hash_Entry;

typedef struct Hash_Table 
{
    struct Hash_Entry **bucketPtr;  /* Buckets in the table */
    int         size;       /* Actual size of array. */
    int         numEntries; /* Number of entries in the table. */
    int         mask;       /* Used to select bits for hashing. */
} Hash_Table;

I want to create an array(or a dynamic array) of this Hash_Table so that when I feel the table is full I can create another table instead of re sizing it

unwind · Accepted Answer · 2012-01-13 11:34:38Z

1

Something like:

void hash_table_init(Hash_Table *table, size_t entries)
{
  size_t i;

  table->size = 0;
  table->numEntries = entries;
  table->bucketPtr = malloc(table->numEntries * sizeof *table->bucketPtr);
  for(i = 0; i < table->numEntries; i++)
    table->bucketPtr[i] = NULL;
  table->mask = 0; /* Not sure how to initialize this. */
}

I don't quite see the point of leaving the initial buckets as pointers, I'd probably just do

typedef struct {
  ...
  Hash_Entry *buckets;
  ...
} Hash_Table;

Assuming that most buckets will actually be used, so why not have them. :)

edited Jan 13, 2012 at 11:34

answered Jan 13, 2012 at 9:52

unwind

402k64 gold badges492 silver badges620 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Community · Accepted Answer · 2017-05-23 12:03:14Z

0

you can create an array using malloc from stdlib

Hash_Table* array = (Hash_Table*)malloc(sizeof(Hash_Table) * 100);

and when the array is full you can do a realloc.

you can have a look at:

Create dynamic sized array of user defined structure

edited May 23, 2017 at 12:03

CommunityBot

11 silver badge

answered Jan 13, 2012 at 9:48

Kumar Alok

2,6328 gold badges27 silver badges38 bronze badges

1 Comment

Ibrar Ahmed Over a year ago

He said he doesn't want to resize that.

Collectives™ on Stack Overflow

how can i create a dynamic array of a hash table in c

2 Answers 2

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related