19 lines
409 B
Python
19 lines
409 B
Python
def inv(a, modulus):
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if a == 0:
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return 0
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lm, hm = 1, 0
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low, high = a % modulus, modulus
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while low > 1:
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r = high//low
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nm, new = hm-lm*r, high-low*r
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lm, low, hm, high = nm, new, lm, low
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return lm % modulus
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def eval_poly_at(poly, x, modulus):
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o, p = 0, 1
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for coeff in poly:
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o += coeff * p
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p = (p * x % modulus)
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return o % modulus
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