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