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98e9d6bdb6
* Fix style of the first ten solutions for Project Euler - Unify the header docstring, and add reference URLs to wikipedia or similar - Fix docstrings to be properly multilined - Add newlines where appropriate - Add doctests where they were missing - Remove doctests that test for the correct solution - fix obvious spelling or grammar mistakes in comments and exception messages - Fix line endings to be UNIX. This makes two of the files seem to have changed completely - no functional changes in any of the solutions were done (except for the spelling fixes mentioned above) * Fix docstrings and main function as per Style Guide
66 lines
1.1 KiB
Python
66 lines
1.1 KiB
Python
"""
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Project Euler Problem 10: https://projecteuler.net/problem=10
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Summation of primes
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The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.
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Find the sum of all the primes below two million.
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References:
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- https://en.wikipedia.org/wiki/Prime_number
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"""
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from math import sqrt
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def is_prime(n: int) -> bool:
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"""
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Returns boolean representing primality of given number num.
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>>> is_prime(2)
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True
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>>> is_prime(3)
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True
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>>> is_prime(27)
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False
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>>> is_prime(2999)
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True
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"""
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for i in range(2, int(sqrt(n)) + 1):
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if n % i == 0:
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return False
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return True
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def solution(n: int = 2000000) -> int:
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"""
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Returns the sum of all the primes below n.
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>>> solution(1000)
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76127
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>>> solution(5000)
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1548136
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>>> solution(10000)
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5736396
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>>> solution(7)
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10
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"""
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if n > 2:
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sum_of_primes = 2
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else:
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return 0
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for i in range(3, n, 2):
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if is_prime(i):
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sum_of_primes += i
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return sum_of_primes
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if __name__ == "__main__":
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print(f"{solution() = }")
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