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https://github.com/Crocmagnon/advent-of-code.git
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94 lines
2.3 KiB
Python
94 lines
2.3 KiB
Python
from collections import defaultdict
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def main(filename: str, expected_part_1: int = None, expected_part_2: int = None):
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print(f"\n+ Running on {filename}")
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with open(filename) as f:
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data = f.read().strip().split("\n")
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counter_part_1 = solve_part_1(data)
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print(f"1. Found {counter_part_1}")
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if expected_part_1:
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assert expected_part_1 == counter_part_1
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counter_part_2 = solve_part_2(data)
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print(f"2. Found {counter_part_2}")
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if expected_part_2:
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assert expected_part_2 == counter_part_2
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def solve_part_1(data):
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count_ones = defaultdict(int)
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total = len(data)
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for binary in data:
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for index, digit in enumerate(binary):
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if digit == "1":
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count_ones[index] += 1
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gamma = ""
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epsilon = ""
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for index in range(len(data[0])):
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most_common = _most_common(count_ones, total, index)
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gamma += most_common
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epsilon += "0" if most_common == "1" else "1"
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return int(gamma, 2) * int(epsilon, 2)
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def _most_common(count_ones, total, index):
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"""
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Return 1 if the most common value is 1, otherwise 0.
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"""
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if count_ones[index] >= total / 2:
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return "1"
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return "0"
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def solve_part_2(data):
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oxygen = _oxygen(data)
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co2 = _co2(data)
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return oxygen * co2
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def _oxygen(data):
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index = 0
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max_index = len(data[0])
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while index < max_index:
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if len(data) == 1:
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return int(data[0], 2)
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ones, zeros = _separate_ones_zeros(data, index)
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index += 1
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if len(ones) >= len(zeros):
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data = ones
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else:
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data = zeros
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return int(data[0], 2)
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def _co2(data):
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index = 0
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max_index = len(data[0])
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while index < max_index:
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if len(data) == 1:
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return int(data[0], 2)
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ones, zeros = _separate_ones_zeros(data, index)
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index += 1
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if len(ones) < len(zeros):
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data = ones
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else:
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data = zeros
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def _separate_ones_zeros(data, index):
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ones = []
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zeros = []
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for binary in data:
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if binary[index] == "1":
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ones.append(binary)
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else:
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zeros.append(binary)
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return ones, zeros
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if __name__ == "__main__":
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main("inputs/day03-test1", expected_part_1=198, expected_part_2=230)
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main("inputs/day03", expected_part_1=1997414, expected_part_2=1032597)
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