60 lines
1.8 KiB
Python
60 lines
1.8 KiB
Python
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# SPDX-License-Identifier: MIT
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# Copyright (c) 2020 Akumatic
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#
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# https://adventofcode.com/2020/day/7
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def readFile() -> list:
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with open(f"{__file__.rstrip('code.py')}input.txt", "r") as f:
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return [line.strip() for line in f.read().strip().split("\n")]
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def parseRules(input) -> dict:
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rules = {}
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amount = {}
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for line in input:
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rule = line.strip(".").split(" contain ")
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bag = rule[0][:-(4 if rule[0][-1]=="g" else 5)]
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if rule[1] == "no other bags":
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rules[bag] = []
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amount[bag] = []
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else:
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contents = [r.split() for r in rule[1].split(", ")]
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rules[bag] = [" ".join(c[1:3]) for c in contents]
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amount[bag] = [int(c[0]) for c in contents]
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return rules, amount
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def can_contain(rules: dict, rule, bag, cache):
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if rule in cache:
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return cache[rule]
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if bag in rules[rule]:
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cache[rule] = True
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else:
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cache[rule] = any(can_contain(rules, b, bag, cache) for b in rules[rule])
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return cache[rule]
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def count_bags(rules: dict, amount: dict, bag, cache):
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if bag in cache:
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return cache[bag]
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if len(rules[bag]) == 0:
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cache[bag] = 0
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return 0
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else:
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sum = 0
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for i in range(len(rules[bag])):
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sum += amount[bag][i] * (count_bags(rules, amount, rules[bag][i], cache) + 1)
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cache[bag] = sum
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return cache[bag]
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def part1(rules: dict) -> int:
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cache = {}
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return sum([can_contain(rules, rule, "shiny gold", cache) for rule in rules])
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def part2(rules: dict, amount: dict) -> int:
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cache = {}
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return count_bags(rules, amount, "shiny gold", cache)
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if __name__ == "__main__":
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rules, amount = parseRules(readFile())
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print(f"Part 1: {part1(rules)}")
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print(f"Part 2: {part2(rules, amount)}")
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