31 lines
956 B
Plaintext
31 lines
956 B
Plaintext
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#!/usr/bin/python3
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from pprint import pprint
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import re
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rules = {}
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with open("input") as fh:
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for ln in fh:
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m = re.fullmatch(r"(.*) bags contain (.*)\.\n", ln)
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container = m.group(1)
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contents = {}
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for c in m.group(2).split(", "):
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if m := re.match(r"(\d+) (.*) bag", c):
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contents[m.group(2)] = int(m.group(1))
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assert container not in rules # Assume only one rule for each container
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rules[container] = contents
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containers = { "shiny gold" }
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while True:
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new_containers = set()
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for c in containers:
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for r in rules.items():
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if c in r[1]:
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new_containers.add(r[0])
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combined_containers = containers | new_containers
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pprint(combined_containers)
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if combined_containers == containers:
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# nothing added, so we are finished
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break
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containers = combined_containers
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print(len(combined_containers - { "shiny gold" }))
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