92 lines
2.4 KiB
Python
92 lines
2.4 KiB
Python
|
#!/usr/bin/env python
|
||
|
|
|
||
|
|
import sys
|
||
|
|
from enum import StrEnum
|
||
|
|
from typing import NamedTuple
|
||
|
|
|
||
|
|
|
||
|
|
class Attribute(StrEnum):
|
||
|
|
COOL = "x"
|
||
|
|
MUSIC = "m"
|
||
|
|
AERODYNAMIC = "a"
|
||
|
|
SHINY = "s"
|
||
|
|
|
||
|
|
|
||
|
|
Part = dict[Attribute, int]
|
||
|
|
|
||
|
|
|
||
|
|
class Rule(NamedTuple):
|
||
|
|
attr: Attribute
|
||
|
|
cmp: str
|
||
|
|
n: int
|
||
|
|
success: str
|
||
|
|
failure: str
|
||
|
|
|
||
|
|
def apply(self, part: Part) -> str:
|
||
|
|
COMP = {
|
||
|
|
"<": lambda x: x < self.n,
|
||
|
|
">": lambda x: x > self.n,
|
||
|
|
}
|
||
|
|
if COMP[self.cmp](part[self.attr]):
|
||
|
|
return self.success
|
||
|
|
return self.failure
|
||
|
|
|
||
|
|
|
||
|
|
Workflow = dict[str, Rule]
|
||
|
|
|
||
|
|
|
||
|
|
def solve(input: str) -> int:
|
||
|
|
def parse_rules(rules: list[str]) -> Workflow:
|
||
|
|
def parse_line(line: str) -> Workflow:
|
||
|
|
name, rules = line.split("{")
|
||
|
|
rules = rules[:-1] # Remove trailing '}'
|
||
|
|
# I translate one rule into a succession of pass/fail transitions
|
||
|
|
res: Workflow = {}
|
||
|
|
raw = rules.split(",")
|
||
|
|
|
||
|
|
for i, rule in enumerate(raw[:-1]):
|
||
|
|
test, success = rule.split(":")
|
||
|
|
attr = Attribute(test[0])
|
||
|
|
cmp = test[1]
|
||
|
|
n = int(test[2:])
|
||
|
|
failure = raw[-1] if (i == len(raw) - 2) else f"{name}_{i + 1}"
|
||
|
|
rule_name = name if i == 0 else f"{name}_{i}"
|
||
|
|
res[rule_name] = Rule(attr, cmp, n, success, failure)
|
||
|
|
|
||
|
|
return res
|
||
|
|
|
||
|
|
return {
|
||
|
|
name: rule for line in map(parse_line, rules) for name, rule in line.items()
|
||
|
|
}
|
||
|
|
|
||
|
|
def parse_parts(parts: list[str]) -> list[Part]:
|
||
|
|
def parse_part(line: str) -> Part:
|
||
|
|
line = line[1:-1] # Remove braces
|
||
|
|
values = {
|
||
|
|
Attribute(name): int(n)
|
||
|
|
for name, n in map(lambda x: x.split("="), line.split(","))
|
||
|
|
}
|
||
|
|
return values
|
||
|
|
|
||
|
|
return [parse_part(line) for line in parts]
|
||
|
|
|
||
|
|
def apply_workflow(part: Part, rules: Workflow) -> bool:
|
||
|
|
state = "in"
|
||
|
|
while state not in ("R", "A"):
|
||
|
|
state = rules[state].apply(part)
|
||
|
|
return state == "A"
|
||
|
|
|
||
|
|
paragraphs = input.split("\n\n")
|
||
|
|
rules = parse_rules(paragraphs[0].splitlines())
|
||
|
|
parts = parse_parts(paragraphs[1].splitlines())
|
||
|
|
return sum(sum(part.values()) for part in parts if apply_workflow(part, rules))
|
||
|
|
|
||
|
|
|
||
|
|
def main() -> None:
|
||
|
|
input = sys.stdin.read()
|
||
|
|
print(solve(input))
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
main()
|