/* a bucket is a linked list, each of whose entries contains a string and its hash */

typedef struct bucket bucket;
struct bucket {
  char *string;
  unsigned long int hash;
  bucket *next;
};
/* By convention, the empty bucket is NULL. */

typedef struct hash_table htbl;
struct hash_table {
  unsigned long int(*hash)(char*);
  bucket **buckets; /* an array of buckets */
  unsigned int n_buckets;
};