19 lines
506 B
Python
19 lines
506 B
Python
def is_prime(N):
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if N < 2:
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return False
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for p in [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31]:
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if N % p == 0: return N == p
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d = N - 1
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s = 0
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while d % 2 == 0:
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d >>= 1
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s += 1
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for a in [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31]:
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if a >= N: continue
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x = pow(a, d, N)
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if x == 1 or x == N - 1: continue
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for _ in range(s - 1):
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x = pow(x, 2, N)
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if x == N - 1: break
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else: return False
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return True |