Python/data_structures/hashing/double_hash.py

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#!/usr/bin/env python3
from .hash_table import HashTable
from .number_theory.prime_numbers import is_prime, next_prime
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class DoubleHash(HashTable):
"""
Hash Table example with open addressing and Double Hash
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"""
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def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def __hash_function_2(self, value, data):
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next_prime_gt = (
next_prime(value % self.size_table)
if not is_prime(value % self.size_table)
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else value % self.size_table
) # gt = bigger than
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return next_prime_gt - (data % next_prime_gt)
def __hash_double_function(self, key, data, increment):
return (increment * self.__hash_function_2(key, data)) % self.size_table
def _collision_resolution(self, key, data=None):
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i = 1
new_key = self.hash_function(data)
while self.values[new_key] is not None and self.values[new_key] != key:
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new_key = (
self.__hash_double_function(key, data, i)
if self.balanced_factor() >= self.lim_charge
else None
)
if new_key is None:
break
else:
i += 1
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return new_key