hash table with linked list Algorithm
Ideally, the hash function will assign each key to a unique bucket, but most hash table designs use an imperfect hash function, which might cause hash collisions where the hash function generates the same index for more than one key. In computing, a hash table (hash map) is a data structure that implements an associative array abstract data type, a structure that can map keys to values.
In January 1953, Hans Peter Luhn write an internal IBM memorandum that used hashing with chaining. gene Amdahl, Elaine M. McGraw, Nathaniel Rochester, and Arthur Samuel implemented a plan use hashing at about the same time. open addressing with linear probing (relatively prime stepping) is credited to Amdahl, but Ershov (in Russia) had the same idea.
from hash_table import HashTable
from collections import deque
class HashTableWithLinkedList(HashTable):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def _set_value(self, key, data):
self.values[key] = deque([]) if self.values[key] is None else self.values[key]
self.values[key].appendleft(data)
self._keys[key] = self.values[key]
def balanced_factor(self):
return (
sum([self.charge_factor - len(slot) for slot in self.values])
/ self.size_table
* self.charge_factor
)
def _collision_resolution(self, key, data=None):
if not (
len(self.values[key]) == self.charge_factor and self.values.count(None) == 0
):
return key
return super()._collision_resolution(key, data)
