advent-of-code/2017/d18/ex2/ex2.py

121 lines
3.5 KiB
Python
Executable file

#!/usr/bin/env python
import collections
import dataclasses
import enum
import sys
from typing import NamedTuple
class Op(enum.StrEnum):
SND = "snd"
SET = "set"
ADD = "add"
MUL = "mul"
MOD = "mod"
RCV = "rcv"
JGZ = "jgz"
class Instruction(NamedTuple):
op: Op
x: str
y: str | None = None
@classmethod
def from_str(cls, input: str) -> "Instruction":
op, *rest = input.split()
return cls(Op(op), *rest)
@dataclasses.dataclass
class Program:
instructions: list[Instruction]
id: dataclasses.InitVar[int]
registers: dict[str, int] = dataclasses.field(init=False)
ip: int = dataclasses.field(init=False, default=0)
receive_queue: collections.deque[int] = dataclasses.field(
init=False, default_factory=collections.deque
)
send_queue: collections.deque[int] = dataclasses.field(
init=False, default_factory=collections.deque
)
values_sent: int = dataclasses.field(init=False, default=0)
def __post_init__(self, id: int) -> None:
self.registers = collections.defaultdict(int)
self.registers["p"] = id
def _resolve(self, y: str | None) -> int:
assert y is not None # Sanity check
try:
return int(y)
except ValueError:
return self.registers[y]
def execute(self) -> None:
while True:
assert 0 <= self.ip < len(self.instructions) # Sanity check
instr = self.instructions[self.ip]
match instr.op:
case Op.SND:
self.send_queue.append(self._resolve(instr.x))
self.values_sent += 1
case Op.SET:
self.registers[instr.x] = self._resolve(instr.y)
case Op.ADD:
self.registers[instr.x] += self._resolve(instr.y)
case Op.MUL:
self.registers[instr.x] *= self._resolve(instr.y)
case Op.MOD:
self.registers[instr.x] %= self._resolve(instr.y)
case Op.RCV:
if not self.receive_queue:
return # Block and wait for a value to be sent
self.registers[instr.x] = self.receive_queue.popleft()
case Op.JGZ:
if self._resolve(instr.x) > 0:
self.ip += self._resolve(instr.y) - 1 # Account auto-increment
self.ip += 1
@property
def is_terminated(self) -> bool:
# Has the program jumped outside the instructions
return self.ip < 0 or self.ip >= len(self.instructions)
@property
def is_blocked(self) -> bool:
if self.is_terminated:
return True
# Is it blocked on a `RCV`
return self.instructions[self.ip].op == Op.RCV and not self.receive_queue
def solve(input: str) -> int:
def parse(input: str) -> list[Instruction]:
return [Instruction.from_str(line) for line in input.splitlines()]
instructions = parse(input)
p0, p1 = Program(instructions, id=0), Program(instructions, id=1)
while True:
if p0.is_blocked and p1.is_blocked:
return p1.values_sent
p0.execute()
p1.execute()
p0.receive_queue.extend(p1.send_queue)
p1.send_queue.clear()
p1.receive_queue.extend(p0.send_queue)
p0.send_queue.clear()
def main() -> None:
input = sys.stdin.read()
print(solve(input))
if __name__ == "__main__":
main()