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5131e3145d
* Fix some ARG002 per file ignores * Fix * updating DIRECTORY.md * Fix review issue * Fix review issue --------- Co-authored-by: MaximSmolskiy <MaximSmolskiy@users.noreply.github.com>
85 lines
2.3 KiB
Python
85 lines
2.3 KiB
Python
#!/usr/bin/env python3
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from .hash_table import HashTable
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class QuadraticProbing(HashTable):
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"""
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Basic Hash Table example with open addressing using Quadratic Probing
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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 _collision_resolution(self, key, data=None): # noqa: ARG002
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"""
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Quadratic probing is an open addressing scheme used for resolving
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collisions in hash table.
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It works by taking the original hash index and adding successive
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values of an arbitrary quadratic polynomial until open slot is found.
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Hash + 1², Hash + 2², Hash + 3² .... Hash + n²
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reference:
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- https://en.wikipedia.org/wiki/Quadratic_probing
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e.g:
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1. Create hash table with size 7
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>>> qp = QuadraticProbing(7)
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>>> qp.insert_data(90)
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>>> qp.insert_data(340)
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>>> qp.insert_data(24)
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>>> qp.insert_data(45)
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>>> qp.insert_data(99)
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>>> qp.insert_data(73)
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>>> qp.insert_data(7)
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>>> qp.keys()
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{11: 45, 14: 99, 7: 24, 0: 340, 5: 73, 6: 90, 8: 7}
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2. Create hash table with size 8
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>>> qp = QuadraticProbing(8)
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>>> qp.insert_data(0)
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>>> qp.insert_data(999)
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>>> qp.insert_data(111)
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>>> qp.keys()
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{0: 0, 7: 999, 3: 111}
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3. Try to add three data elements when the size is two
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>>> qp = QuadraticProbing(2)
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>>> qp.insert_data(0)
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>>> qp.insert_data(999)
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>>> qp.insert_data(111)
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>>> qp.keys()
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{0: 0, 4: 999, 1: 111}
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4. Try to add three data elements when the size is one
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>>> qp = QuadraticProbing(1)
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>>> qp.insert_data(0)
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>>> qp.insert_data(999)
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>>> qp.insert_data(111)
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>>> qp.keys()
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{4: 999, 1: 111}
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"""
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i = 1
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new_key = self.hash_function(key + i * i)
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while self.values[new_key] is not None and self.values[new_key] != key:
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i += 1
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new_key = (
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self.hash_function(key + i * i)
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if not self.balanced_factor() >= self.lim_charge
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else None
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)
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if new_key is None:
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break
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return new_key
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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