Advent of Code 2020 day 1
My Python solution for Advent of Code 2020 day 1. I’ve cleaned this up a wee bit since submitting my answers, but the essence of it hasn’t changed. I did use itertools.permutations at first, which happened to work because the loop bails out as soon as it finds a solution, but I changed it to itertools.combinations for readability.
from pathlib import Path
from itertools import combinations
from math import prod
import unittest
def get_input():
input_file = Path(__file__).parent / 'day_01_input.txt'
with open(input_file) as file:
return [int(line.strip()) for line in file.readlines()]
def run(input, length):
for p in combinations(input, length):
if sum(p) == 2020:
return(prod(p))
class TestExamples(unittest.TestCase):
def setUp(self):
self.input = [1721,979,366,299,675,1456]
def test_part_one(self):
self.assertEqual(run(self.input, 2), 514579)
def test_part_two(self):
self.assertEqual(run(self.input, 3), 241861950)
if __name__ == '__main__':
print(f'Part one: {run(get_input(), 2)}')
print(f'Part two: {run(get_input(), 3)}')