29 lines
678 B
Python
29 lines
678 B
Python
# Algorithm from https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes#Pseudocode
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def primesUpTo(n):
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assert n >= 2, "n must be >= 2"
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A = [True for i in range(n+1)]
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for i in range(2, n+1):
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if A[i]:
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for j in range(i**2, n+1, i):
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A[j] = False
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return set([i for i in range(2, n+1) if A[i]])
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def main():
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# Testing:
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s = primesUpTo(1000)
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print(s)
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# Do some checks:
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assert primesUpTo(30) == {2,3,5,7,11,13,17,19,23,29}
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assert len(primesUpTo(1000)) == 168
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assert len(primesUpTo(7918)) == 999
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assert len(primesUpTo(7919)) == 1000
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print("All tests passed!")
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if __name__ == "__main__":
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main()
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