108 lines
2.9 KiB
Python
108 lines
2.9 KiB
Python
|
#!/usr/bin/env python
|
||
|
|
|
||
|
|
import dataclasses
|
||
|
|
import enum
|
||
|
|
import sys
|
||
|
|
|
||
|
|
|
||
|
|
@dataclasses.dataclass
|
||
|
|
class Registers:
|
||
|
|
reg_a: int
|
||
|
|
reg_b: int
|
||
|
|
reg_c: int
|
||
|
|
|
||
|
|
|
||
|
|
class Instruction(enum.IntEnum):
|
||
|
|
ADV = 0
|
||
|
|
BXL = 1
|
||
|
|
BST = 2
|
||
|
|
JNZ = 3
|
||
|
|
BXC = 4
|
||
|
|
OUT = 5
|
||
|
|
BDV = 6
|
||
|
|
CDV = 7
|
||
|
|
|
||
|
|
|
||
|
|
@dataclasses.dataclass
|
||
|
|
class Computer:
|
||
|
|
registers: Registers
|
||
|
|
program: list[int]
|
||
|
|
ip: int = 0
|
||
|
|
|
||
|
|
def _resolve_combo_operand(self, operand: int) -> int:
|
||
|
|
assert operand != 7 # Sanity check
|
||
|
|
if 0 <= operand <= 3:
|
||
|
|
return operand
|
||
|
|
if operand == 4:
|
||
|
|
return self.registers.reg_a
|
||
|
|
if operand == 5:
|
||
|
|
return self.registers.reg_b
|
||
|
|
if operand == 6:
|
||
|
|
return self.registers.reg_c
|
||
|
|
assert False # Sanity check
|
||
|
|
|
||
|
|
# Returns False if the computer is halted
|
||
|
|
# `output` is an out parameter
|
||
|
|
def step(self, output: list[int]) -> bool:
|
||
|
|
# NOTE: also accounting for operand in overflow check here
|
||
|
|
if (self.ip + 1) >= len(self.program):
|
||
|
|
return False
|
||
|
|
|
||
|
|
instr, literal_operand = (
|
||
|
|
Instruction(self.program[self.ip]),
|
||
|
|
self.program[self.ip + 1],
|
||
|
|
)
|
||
|
|
combo_operand = self._resolve_combo_operand(literal_operand)
|
||
|
|
|
||
|
|
ip_delta = 2
|
||
|
|
match instr:
|
||
|
|
case Instruction.ADV:
|
||
|
|
self.registers.reg_a //= 2**combo_operand
|
||
|
|
case Instruction.BXL:
|
||
|
|
self.registers.reg_b ^= literal_operand
|
||
|
|
case Instruction.BST:
|
||
|
|
self.registers.reg_b = combo_operand % 8
|
||
|
|
case Instruction.JNZ:
|
||
|
|
if self.registers.reg_a != 0:
|
||
|
|
self.ip = literal_operand
|
||
|
|
ip_delta = 0
|
||
|
|
case Instruction.BXC:
|
||
|
|
self.registers.reg_b ^= self.registers.reg_c
|
||
|
|
case Instruction.OUT:
|
||
|
|
output.append(combo_operand % 8)
|
||
|
|
case Instruction.BDV:
|
||
|
|
self.registers.reg_b = self.registers.reg_a // 2**combo_operand
|
||
|
|
case Instruction.CDV:
|
||
|
|
self.registers.reg_c = self.registers.reg_a // 2**combo_operand
|
||
|
|
self.ip += ip_delta
|
||
|
|
|
||
|
|
return True
|
||
|
|
|
||
|
|
|
||
|
|
def solve(input: str) -> str:
|
||
|
|
def parse_registers(input: list[str]) -> Registers:
|
||
|
|
def parse_register(input: str) -> int:
|
||
|
|
return int(input.split(": ")[1])
|
||
|
|
|
||
|
|
return Registers(*map(parse_register, input))
|
||
|
|
|
||
|
|
def parse(input: str) -> Computer:
|
||
|
|
registers, program_str = input.split("\n\n")
|
||
|
|
program = list(map(int, program_str.removeprefix("Program: ").split(",")))
|
||
|
|
return Computer(parse_registers(registers.splitlines()), program)
|
||
|
|
|
||
|
|
computer = parse(input)
|
||
|
|
output: list[int] = []
|
||
|
|
while computer.step(output):
|
||
|
|
pass
|
||
|
|
return ",".join(str(n) for n in output)
|
||
|
|
|
||
|
|
|
||
|
|
def main() -> None:
|
||
|
|
input = sys.stdin.read()
|
||
|
|
print(solve(input))
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
main()
|