29 lines
916 B
Python
29 lines
916 B
Python
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from math import log, floor
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class Memoize:
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"""Helper class to memoize a decorated function."""
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def __init__(self, function):
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self.function = function
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self.memo = {}
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def __call__(self, *args):
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if not args in self.memo:
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self.memo[args] = self.function(*args)
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return self.memo[args]
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@Memoize
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def pdi(power: int, base: int, number: int) -> int:
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"""Computes the perfect digital invariant."""
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return sum(pow((number % pow(base, i + 1) - number % pow(base, i)) / pow(base, i), power) for i in range(0, floor(log(number, base)) + 1))
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def isHappy(number: int, base: int = 10) -> bool:
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"""Check if a number is happy in a given base. Defaults to base 10."""
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seen = set()
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while number > 1 and number not in seen:
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seen.add(number)
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number = pdi(2, base, number)
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return number == 1
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print(isHappy(19))
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