351 lines
11 KiB
Python
351 lines
11 KiB
Python
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#!/usr/bin/env python
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import sys
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from copy import deepcopy
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from dataclasses import dataclass, field
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from enum import Enum, IntEnum, auto
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from typing import List, NamedTuple
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class ParameterMode(IntEnum):
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POSITION = 0 # Acts on address
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IMMEDIATE = 1 # Acts on the immediate value
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RELATIVE = 2 # Acts on offset to relative base
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class Instruction(NamedTuple):
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address: int # The address of the instruction, for convenience
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op: int # The opcode
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p1_mode: ParameterMode # Which mode is the first parameter in
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p2_mode: ParameterMode # Which mode is the second parameter in
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p3_mode: ParameterMode # Which mode is the third parameter in
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def lookup_ops(index: int, memory: List[int]) -> Instruction:
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digits = list(map(int, str(memory[index])))
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a, b, c, d, e = [0] * (5 - len(digits)) + digits # Pad with default values
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return Instruction(
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address=index,
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op=d * 10 + e,
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p1_mode=ParameterMode(c),
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p2_mode=ParameterMode(b),
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p3_mode=ParameterMode(a),
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)
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class InputInterrupt(Exception):
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pass
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class OutputInterrupt(Exception):
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pass
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@dataclass
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class Computer:
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memory: List[int] # Memory space
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rip: int = 0 # Instruction pointer
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input_list: List[int] = field(default_factory=list)
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output_list: List[int] = field(default_factory=list)
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is_halted: bool = field(default=False, init=False)
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relative_base: int = field(default=0, init=False)
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def run(self) -> None:
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while not self.is_halted:
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self.run_single()
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def run_no_output_interrupt(self) -> None:
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while not self.is_halted:
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try:
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self.run_single()
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except OutputInterrupt:
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continue
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def run_single(self): # Returns True when halted
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instr = lookup_ops(self.rip, self.memory)
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if instr.op == 99: # Halt
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self.is_halted = True
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elif instr.op == 1: # Sum
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self._do_addition(instr)
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elif instr.op == 2: # Multiplication
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self._do_multiplication(instr)
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elif instr.op == 3: # Load from input
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self._do_input(instr)
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elif instr.op == 4: # Store to output
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self._do_output(instr)
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elif instr.op == 5: # Jump if true
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self._do_jump_if_true(instr)
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elif instr.op == 6: # Jump if false
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self._do_jump_if_false(instr)
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elif instr.op == 7: # Less than
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self._do_less_than(instr)
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elif instr.op == 8: # Equal to
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self._do_equal_to(instr)
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elif instr.op == 9: # Change relative base
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self._do_change_relative_base(instr)
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else:
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assert False # Sanity check
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def _fill_to_addres(self, address: int) -> None:
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values = address - len(self.memory) + 1
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if values <= 0:
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return
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for __ in range(values):
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self.memory.append(0)
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def _get_value(self, mode: ParameterMode, val: int) -> int:
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if mode == ParameterMode.POSITION:
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assert 0 <= val # Sanity check
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self._fill_to_addres(val)
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return self.memory[val]
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elif mode == ParameterMode.RELATIVE:
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val += self.relative_base
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assert 0 <= val # Sanity check
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self._fill_to_addres(val)
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return self.memory[val]
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assert mode == ParameterMode.IMMEDIATE # Sanity check
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return val
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def _set_value(self, mode: ParameterMode, address: int, value: int) -> None:
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if mode == ParameterMode.RELATIVE:
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address += self.relative_base
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else:
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assert mode == ParameterMode.POSITION # Sanity check
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assert address >= 0 # Sanity check
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self._fill_to_addres(address)
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self.memory[address] = value
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def _do_addition(self, instr: Instruction) -> None:
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lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
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dest = self.memory[instr.address + 3]
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self._set_value(instr.p3_mode, dest, lhs + rhs)
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self.rip += 4 # Length of the instruction
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def _do_multiplication(self, instr: Instruction) -> None:
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lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
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dest = self.memory[instr.address + 3]
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self._set_value(instr.p3_mode, dest, lhs * rhs)
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self.rip += 4 # Length of the instruction
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def _do_input(self, instr: Instruction) -> None:
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if len(self.input_list) == 0:
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raise InputInterrupt # No input, halt until an input is provided
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value = int(self.input_list.pop(0))
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param = self.memory[instr.address + 1]
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self._set_value(instr.p1_mode, param, value)
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self.rip += 2 # Length of the instruction
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def _do_output(self, instr: Instruction) -> None:
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value = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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self.output_list.append(value)
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self.rip += 2 # Length of the instruction
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raise OutputInterrupt # Alert that we got an output to give
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def _do_jump_if_true(self, instr: Instruction) -> None:
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cond = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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value = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
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if cond != 0:
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self.rip = value
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else:
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self.rip += 3 # Length of the instruction
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def _do_jump_if_false(self, instr: Instruction) -> None:
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cond = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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value = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
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if cond == 0:
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self.rip = value
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else:
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self.rip += 3 # Length of the instruction
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def _do_less_than(self, instr: Instruction) -> None:
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lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
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dest = self.memory[instr.address + 3]
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self._set_value(instr.p3_mode, dest, 1 if lhs < rhs else 0)
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self.rip += 4 # Length of the instruction
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def _do_equal_to(self, instr: Instruction) -> None:
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lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
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dest = self.memory[instr.address + 3]
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self._set_value(instr.p3_mode, dest, 1 if lhs == rhs else 0)
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self.rip += 4 # Length of the instruction
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def _do_change_relative_base(self, instr: Instruction) -> None:
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value = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
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self.relative_base += value
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self.rip += 2 # Length of the instruction
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class Position(NamedTuple):
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x: int
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y: int
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class Direction(Enum):
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NORTH = auto()
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WEST = auto()
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SOUTH = auto()
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EAST = auto()
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DIRECTIONS = [d for d in Direction]
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ARROW_DIRECTION = {
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"^": Direction.NORTH,
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"v": Direction.SOUTH,
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"<": Direction.WEST,
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">": Direction.EAST,
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}
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DIRECTION_OFFSET = {
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Direction.NORTH: (-1, 0),
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Direction.SOUTH: (1, 0),
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Direction.WEST: (0, -1),
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Direction.EAST: (0, 1),
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}
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def turn(d: Direction, turn: str) -> Direction:
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def turn_left() -> Direction:
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return DIRECTIONS[(DIRECTIONS.index(d) + 1) % len(DIRECTIONS)]
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def turn_right() -> Direction:
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return DIRECTIONS[DIRECTIONS.index(d) - 1]
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if turn == "L":
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return turn_left()
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elif turn == "R":
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return turn_right()
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assert False # Sanity check
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def find_arrow(mapped_view: List[List[str]]) -> Position:
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for x in range(len(mapped_view)):
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for y in range(len(mapped_view[0])):
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if mapped_view[x][y] in ARROW_DIRECTION:
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return Position(x, y)
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assert False # Sanity check
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def get_path(mapped_view: List[List[str]]) -> List[str]:
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pos = find_arrow(mapped_view)
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def pos_is_valid(p: Position) -> bool:
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return 0 <= p.x < len(mapped_view) and 0 <= p.y < len(mapped_view[0])
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def pos_is_scaffold(p: Position) -> bool:
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return pos_is_valid(p) and mapped_view[p.x][p.y] != "."
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direction = ARROW_DIRECTION[mapped_view[pos.x][pos.y]]
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ans: List[str] = []
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def advance_until_stopped(turn_string: str) -> bool:
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nonlocal pos
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nonlocal direction
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d = turn(direction, turn_string)
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offset = DIRECTION_OFFSET[d]
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neighbor = Position(*(a + b for a, b in zip(pos, offset)))
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tot = 0
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while pos_is_scaffold(neighbor):
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tot += 1
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mapped_view[pos.x][pos.y] = "@"
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pos = neighbor
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neighbor = Position(*(a + b for a, b in zip(pos, offset)))
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if tot == 0:
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return False
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direction = d
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ans.append(turn_string)
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ans.append(str(tot))
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return True
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has_no_neighbors = False
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while not has_no_neighbors:
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for turn_string in ("L", "R"):
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if advance_until_stopped(turn_string):
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break
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else:
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has_no_neighbors = True
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return ans
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def sequitur_algorithm(path: str) -> None:
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# FIXME: seems like a good candidate for compression
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pass
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def main() -> None:
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memory = [int(n) for n in sys.stdin.read().split(",")]
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camera = Computer(deepcopy(memory))
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camera.run_no_output_interrupt()
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view = "".join(chr(c) for c in camera.output_list)
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mapped_view = [[c for c in line] for line in view.split("\n") if line != ""]
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path = get_path(mapped_view)
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print(path)
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# I didn't want to write the compression algorithm when I could just use Vim
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# The answere is A,B,B,A,C,A,A,C,B,C
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# A: R,8,L,12,R,8
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# B: R,12,L,8,R,10
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# C: R,8,L,8,L,8,R,8,R,10
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ans = "A,B,B,A,C,A,A,C,B,C"
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A = "R,8,L,12,R,8"
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B = "R,12,L,8,R,10"
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C = "R,8,L,8,L,8,R,8,R,10"
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assert len(ans) <= 20 # Sanity check
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assert len(A) <= 20 # Sanity check
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assert len(B) <= 20 # Sanity check
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assert len(C) <= 20 # Sanity check
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memory[0] = 2 # Wake up the robot
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robot = Computer(memory)
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for c in ans:
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robot.input_list.append(ord(c))
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robot.input_list.append(ord("\n"))
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for c in A:
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robot.input_list.append(ord(c))
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robot.input_list.append(ord("\n"))
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for c in B:
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robot.input_list.append(ord(c))
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robot.input_list.append(ord("\n"))
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for c in C:
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robot.input_list.append(ord(c))
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robot.input_list.append(ord("\n"))
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for c in "n\n": # Do not output the video feed
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robot.input_list.append(ord(c))
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robot.run_no_output_interrupt()
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print(robot.output_list.pop())
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if __name__ == "__main__":
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main()
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