"""
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Advent of Code 2021 - Day 07
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Run with:
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python puzzles/day07.py inputs/day07.txt
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"""
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import pathlib
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import sys
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from statistics import median
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from typing import List, Tuple
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class AlignCrabSubs:
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positions: List[int]
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def __init__(self, positions: List[int]) -> None:
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self.positions = positions
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def calc_fuel(self, pricey: bool = False) -> int:
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if not pricey:
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return self.calc_fuel_simple(median(self.positions))
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fuel = None
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for position in range(len(set(self.positions)) + 1):
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price = self.calc_fuel_pricey(position)
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if fuel is None or fuel > price:
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fuel = price
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return fuel
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def calc_fuel_simple(self, target: int) -> int:
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return int(sum(abs(num - target) for num in self.positions))
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def calc_fuel_pricey(self, target: int) -> int:
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fuel = 0
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for num in self.positions:
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num_range = abs(num - target) + 1
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fuel += sum(range(num_range))
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return int(fuel)
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def part1(inputs: List[int]) -> int:
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subs = AlignCrabSubs(inputs)
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return subs.calc_fuel()
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def part2(inputs: List[int]) -> int:
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subs = AlignCrabSubs(inputs)
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return subs.calc_fuel(pricey=True)
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def parse(inputs: str) -> List[int]:
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"""Parse the input string"""
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return [int(value) for value in inputs.split(",")]
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def solve(path: str) -> Tuple[int, int]:
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"""Solve the puzzle"""
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puzzle_input = parse(pathlib.Path(path).read_text().strip())
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part1_result = part1(puzzle_input)
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part2_result = part2(puzzle_input)
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return part1_result, part2_result
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def main() -> None:
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for path in sys.argv[1:]:
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print(f"Input File: {path}")
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part1_result, part2_result = solve(path)
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print(f"Part 1 Result: {part1_result}")
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print(f"Part 2 Result: {part2_result}")
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if __name__ == "__main__":
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main()
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