36 lines
708 B
Python
36 lines
708 B
Python
# Arithmetics functions implementaton
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def modpow(a: int, b: int, m: int) -> int:
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result = 1
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while b > 0:
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if (b & 1) > 0:
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result = (result * a) % m
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b = b >> 1
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a = (a * a) % m
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return result
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def gcd(a: int, b: int) -> int:
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# if b = 0 return a
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if b == 0:
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return a
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# return gcd(b, a % b) because gcd(a, b) = gcd(b, rem(a, b))
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return gcd(b, a % b)
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def mod_inverse(A: int, M: int) -> int:
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m0 = M
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y = 0
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x = 1
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if (M == 1):
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return 0
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while (A > 1):
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q = A // M
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t = M
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M = A % M
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A = t
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t = y
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y = x - q * y
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x = t
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if (x < 0):
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x = x + m0
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return x
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