Improve sieve of eratosthenes and remove duplicate #5043
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poyea
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| # Do even numbers separately | ||
| primes = [2] | ||
| for i in range(4, num + 1, 2): | ||
| sieve[i] = False |
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I think we don't want to optimize it like this to keep its original algorithm. https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes#Algorithm_and_variants
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It is the same algorithm, but since 2 is the only even prime, you can check it seperately and remove unnecessary tests
poyea
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Oct 6, 2021
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| p = 3 | ||
| while p * p <= num: |
poyea
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Oct 6, 2021
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| >>> prime_sieve_eratosthenes(10) | ||
| 2,3,5,7, | ||
| >>> prime_sieve_eratosthenes(20) | ||
| 2,3,5,7,11,13,17,19, |
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Move these tests to the existing file.
poyea
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Oct 6, 2021
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| return prime | ||
| return primes | ||
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| if __name__ == "__main__": |
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Suggested change
| if __name__ == "__main__": | |
| if __name__ == "__main__": | |
| import doctest | |
| doctest.testmod() |
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Describe your change:
I removed a duplicate of sieve of eratosthenes in favour of the older one, and improved the older one by iterating by 2 elements each time and removing the math dependency
Checklist:
Fixes: #{$ISSUE_NO}.