2022: d11: ex2: add solution
This commit is contained in:
parent
efb846e460
commit
93cac379e0
95
2022/d11/ex2/ex2.py
Executable file
95
2022/d11/ex2/ex2.py
Executable file
|
@ -0,0 +1,95 @@
|
|||
#!/usr/bin/env python
|
||||
|
||||
import dataclasses
|
||||
import math
|
||||
import sys
|
||||
from collections import Counter, deque
|
||||
from typing import Literal, Optional
|
||||
|
||||
|
||||
@dataclasses.dataclass
|
||||
class Operation:
|
||||
lhs: Optional[int]
|
||||
operator: Literal["+", "*"]
|
||||
rhs: Optional[int]
|
||||
|
||||
def __call__(self, old: int) -> int:
|
||||
lhs = old if self.lhs is None else self.lhs
|
||||
rhs = old if self.rhs is None else self.rhs
|
||||
|
||||
if self.operator == "*":
|
||||
return lhs * rhs
|
||||
if self.operator == "+":
|
||||
return lhs + rhs
|
||||
assert False
|
||||
|
||||
@classmethod
|
||||
def from_input(cls, input: str) -> "Operation":
|
||||
assert input.startswith(" Operation: new = ")
|
||||
lhs, op, rhs = input.split()[-3:]
|
||||
|
||||
assert op in ("+", "*") # Sanity check
|
||||
|
||||
return cls(
|
||||
None if lhs == "old" else int(lhs),
|
||||
op, # type: ignore
|
||||
None if rhs == "old" else int(rhs),
|
||||
)
|
||||
|
||||
|
||||
@dataclasses.dataclass
|
||||
class Monkey:
|
||||
items: deque[int]
|
||||
operation: Operation
|
||||
test_divisor: int
|
||||
transfer: dict[bool, int]
|
||||
|
||||
@classmethod
|
||||
def from_input(cls, input: list[str]) -> "Monkey":
|
||||
# Sanity checks
|
||||
assert input[0].startswith("Monkey ")
|
||||
assert "divisible by" in input[3]
|
||||
assert "true" in input[4]
|
||||
assert "false" in input[5]
|
||||
|
||||
items = deque(
|
||||
int(n) for n in input[1].removeprefix(" Starting items: ").split(",")
|
||||
)
|
||||
operation = Operation.from_input(input[2])
|
||||
divisor = int(input[3].split()[-1])
|
||||
transfer = {
|
||||
True: int(input[4].split()[-1]),
|
||||
False: int(input[5].split()[-1]),
|
||||
}
|
||||
return Monkey(items, operation, divisor, transfer)
|
||||
|
||||
|
||||
def solve(input: list[str]) -> int:
|
||||
def do_round(monkeys: list[Monkey], counts: dict[int, int]) -> None:
|
||||
modulo = math.prod(monkey.test_divisor for monkey in monkeys)
|
||||
for i, monkey in enumerate(monkeys):
|
||||
counts[i] += len(monkey.items)
|
||||
while monkey.items:
|
||||
item = monkey.items.popleft()
|
||||
item = monkey.operation(item)
|
||||
item %= modulo # Keep a reasonable range on this value
|
||||
target = monkey.transfer[(item % monkey.test_divisor) == 0]
|
||||
monkeys[target].items.append(item)
|
||||
|
||||
monkeys = [Monkey.from_input(monkey_spec.splitlines()) for monkey_spec in input]
|
||||
counts: Counter[int] = Counter()
|
||||
|
||||
for _ in range(10_000):
|
||||
do_round(monkeys, counts)
|
||||
|
||||
((_, a), (_, b)) = counts.most_common(2)
|
||||
return a * b
|
||||
|
||||
|
||||
def main() -> None:
|
||||
input = sys.stdin.read().split("\n\n")
|
||||
print(solve(input))
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
main()
|
Loading…
Reference in a new issue