My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add more utility functions
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2016/utils.py
+38
2016/utils.py
···
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import math
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import operator
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from functools import total_ordering
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LETTERS = [x for x in 'abcdefghijklmnopqrstuvwxyz']
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VOWELS = {'a', 'e', 'i', 'o', 'u'}
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CONSONANTS = set(x for x in LETTERS if x not in VOWELS)
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def mul(lst):
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"""Like sum(), but for multiplication."""
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return reduce(operator.mul, lst, 1)
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def factors(n):
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"""Returns the factors of n."""
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return sorted(
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x for tup in (
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[i, n//i] for i in range(1, int(n**0.5) + 1)
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if n % i == 0)
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for x in tup)
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def primes(n):
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"""Returns the sorted list of primes in the range [2, n]"""
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limit = n + 1
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not_prime = set()
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primes = []
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for i in range(2, limit):
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if i in not_prime:
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continue
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for f in range(i*2, limit, i):
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not_prime.add(f)
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primes.append(i)
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return primes
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@total_ordering