81 lines
2.3 KiB
Python
81 lines
2.3 KiB
Python
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from fractions import Fraction
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from sys import maxint
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class PAdic:
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p = 2
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def __init__(self):
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self.val = '' # current known value
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self.prec = 0 # current known precision
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self.order = 0 # order/valuation of number
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pass # initialize object as subclass perhaps
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def get(self, prec):
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'Return value of number with given precision.'
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raise NotImplementedError
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# return value with precision up to 32 bits
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def __int__(self):
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return int(self.get(32), p)
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def __str__(self):
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return self.get(32)
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def __repr__(self):
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pass
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# arithmetic operations
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def __add__(self, other):
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return PAdicAdd(self, other)
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def __radd__(self, other):
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return PAdicAdd(other, self)
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def __sub__(self, other):
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return PAdicAdd(self, PAdicInv(other))
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def __rsub__(self, other):
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return PAdicAdd(other, PAdicInv(self))
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def __smul__(self, other):
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return PAdicMul(self, other)
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def __rsub__(self, other):
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return PAdicMul(other, self)
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# p-adic norm
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def __abs__(self):
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if self.order == maxint:
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return 0
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norm = Fraction(1)
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if self.order > 0:
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norm.numerator = p ** self.order
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if self.order < 0:
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norm.denominator = p ** self.order
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return norm
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class PAdicConst(PAdic):
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def __init__(self, value):
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PAdic.__init__(self)
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value = Fraction(value)
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# calculate valuation
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if value == 0:
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self.value = value
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self.val = '0'
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return
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self.norm = Fraction(1)
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self.order = 0
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while not value.numerator % p:
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self.norm /= p
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self.order += 1
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value.numerator /= p
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while not value.denominator % p:
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self.norm *= p
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valuation -= 1
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value.denominator /= p
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self.value = value
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def get(self, prec):
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'Return value of constant with given precision.'
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if self.value == 0:
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return self.val
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while self.prec < prec:
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# update val based on value
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self.prec += 1
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return self.val # TODO add decimal point or trailing zeros
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