import collections from typing import List, TextIO, Tuple, Union def read_program(data: TextIO) -> List[int]: line = next(data) return [int(i) for i in line.split(',')] class Computer: program: List[int] pointer: int input: collections.deque[int] output: collections.deque[int] def __init__(self, program: List[int], pointer: int = 0) -> None: self.program = program self.pointer = pointer self.input = collections.deque() self.output = collections.deque() def _mode_and_key(self, item: Union[int, Tuple[int, int]]) -> Tuple[int, int]: if isinstance(item, int): return 0, item else: mode, key = item return mode, self.program[self.pointer + key] def __getitem__(self, item: Union[int, Tuple[int, int]]) -> int: mode, key = self._mode_and_key(item) if mode == 0: self._ensure_length(key + 1) return self.program[key] elif mode == 1: return key else: raise ValueError(f'Unsupported mode "{mode}"') def __setitem__(self, item: Union[int, Tuple[int, int]], value: int) -> None: mode, key = self._mode_and_key(item) if mode == 0: self._ensure_length(key + 1) self.program[key] = value elif mode == 1: raise ValueError('Cannot assign to an immediate') else: raise ValueError(f'Unsupported mode "{mode}"') def _ensure_length(self, length: int) -> None: if len(self.program) < length: # Double current program size with 0s self.program.extend(0 for _ in range(len(self.program))) def run(self) -> None: """ Run until failure """ while self._execute_current(): pass def _execute_current(self) -> bool: """ Execute a single instruction :return: True if the program should continue """ pointer = self.pointer instruction = self[pointer] opcode = instruction % 100 mode = [ (instruction // 100) % 10, (instruction // 1000) % 10, (instruction // 10000) % 10, ] if opcode == 1: # Add self[mode[2], 3] = self[mode[0], 1] + self[mode[1], 2] self.pointer += 4 elif opcode == 2: # Multiply self[mode[2], 3] = self[mode[0], 1] * self[mode[1], 2] self.pointer += 4 elif opcode == 3: # Input self[mode[0], 1] = self.input.popleft() self.pointer += 2 elif opcode == 4: # Output self.output.append(self[mode[0], 1]) self.pointer += 2 elif opcode == 5: # Jump if true if self[mode[0], 1] != 0: self.pointer = self[mode[1], 2] else: self.pointer += 3 elif opcode == 6: # Jump if false if self[mode[0], 1] == 0: self.pointer = self[mode[1], 2] else: self.pointer += 3 elif opcode == 7: # Less than if self[mode[0], 1] < self[mode[1], 2]: self[mode[2], 3] = 1 else: self[mode[2], 3] = 0 self.pointer += 4 elif opcode == 8: # Equals if self[mode[0], 1] == self[mode[1], 2]: self[mode[2], 3] = 1 else: self[mode[2], 3] = 0 self.pointer += 4 elif opcode == 99: # Halt return False else: raise ValueError(f'Unknown opcode {opcode} at {pointer}') return True