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Create polynomial_hash.py #9160

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Create polynomial_hash.py #9160

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566fa0e
Create polynomial_hash.py
prasad-chavan1 Oct 1, 2023
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[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] Oct 1, 2023
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25 changes: 25 additions & 0 deletions hashes/polynomial_hash.py
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"""
Calculate the hash of a string using a polynomial rolling hash function.
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If this is a polynomial rolling hash, then why not name the file and function polynomial_rolling_hash?


Args:
s (str): The input string to be hashed.
p (int): A prime number to serve as the base for the polynomial hash (default is 31).
m (int): A large prime number to prevent integer overflow (default is 10^9 + 9).

Returns: int: The computed hash value.
Wikipedia :: https://en.wikipedia.org/wiki/Hash_function
"""


def polynomial_hash(s, p=31, m=10**9 + 9):
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Please provide return type hint for the function: polynomial_hash. If the function does not return a value, please provide the type hint as: def function() -> None:

As there is no test file in this pull request nor any test function or class in the file hashes/polynomial_hash.py, please provide doctest for the function polynomial_hash

Please provide type hint for the parameter: s

Please provide descriptive name for the parameter: s

Please provide type hint for the parameter: p

Please provide descriptive name for the parameter: p

Please provide type hint for the parameter: m

Please provide descriptive name for the parameter: m

hash_value = 0
p_pow = 1
for char in s:
char_value = ord(char) - ord("a") + 1 # Convert character to a numerical value
hash_value = (hash_value + char_value * p_pow) % m
p_pow = (p_pow * p) % m
return hash_value


print(polynomial_hash("PythonLanguage"))
# Output: 877483825
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Please encapsulate all driver code in a __main__ block.