advent-of-code/2019/d17/ex2/ex2.py

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2019-12-17 13:40:47 +01:00
#!/usr/bin/env python
import sys
from copy import deepcopy
from dataclasses import dataclass, field
from enum import Enum, IntEnum, auto
from typing import List, NamedTuple
class ParameterMode(IntEnum):
POSITION = 0 # Acts on address
IMMEDIATE = 1 # Acts on the immediate value
RELATIVE = 2 # Acts on offset to relative base
class Instruction(NamedTuple):
address: int # The address of the instruction, for convenience
op: int # The opcode
p1_mode: ParameterMode # Which mode is the first parameter in
p2_mode: ParameterMode # Which mode is the second parameter in
p3_mode: ParameterMode # Which mode is the third parameter in
def lookup_ops(index: int, memory: List[int]) -> Instruction:
digits = list(map(int, str(memory[index])))
a, b, c, d, e = [0] * (5 - len(digits)) + digits # Pad with default values
return Instruction(
address=index,
op=d * 10 + e,
p1_mode=ParameterMode(c),
p2_mode=ParameterMode(b),
p3_mode=ParameterMode(a),
)
class InputInterrupt(Exception):
pass
class OutputInterrupt(Exception):
pass
@dataclass
class Computer:
memory: List[int] # Memory space
rip: int = 0 # Instruction pointer
input_list: List[int] = field(default_factory=list)
output_list: List[int] = field(default_factory=list)
is_halted: bool = field(default=False, init=False)
relative_base: int = field(default=0, init=False)
def run(self) -> None:
while not self.is_halted:
self.run_single()
def run_no_output_interrupt(self) -> None:
while not self.is_halted:
try:
self.run_single()
except OutputInterrupt:
continue
def run_single(self): # Returns True when halted
instr = lookup_ops(self.rip, self.memory)
if instr.op == 99: # Halt
self.is_halted = True
elif instr.op == 1: # Sum
self._do_addition(instr)
elif instr.op == 2: # Multiplication
self._do_multiplication(instr)
elif instr.op == 3: # Load from input
self._do_input(instr)
elif instr.op == 4: # Store to output
self._do_output(instr)
elif instr.op == 5: # Jump if true
self._do_jump_if_true(instr)
elif instr.op == 6: # Jump if false
self._do_jump_if_false(instr)
elif instr.op == 7: # Less than
self._do_less_than(instr)
elif instr.op == 8: # Equal to
self._do_equal_to(instr)
elif instr.op == 9: # Change relative base
self._do_change_relative_base(instr)
else:
assert False # Sanity check
def _fill_to_addres(self, address: int) -> None:
values = address - len(self.memory) + 1
if values <= 0:
return
for __ in range(values):
self.memory.append(0)
def _get_value(self, mode: ParameterMode, val: int) -> int:
if mode == ParameterMode.POSITION:
assert 0 <= val # Sanity check
self._fill_to_addres(val)
return self.memory[val]
elif mode == ParameterMode.RELATIVE:
val += self.relative_base
assert 0 <= val # Sanity check
self._fill_to_addres(val)
return self.memory[val]
assert mode == ParameterMode.IMMEDIATE # Sanity check
return val
def _set_value(self, mode: ParameterMode, address: int, value: int) -> None:
if mode == ParameterMode.RELATIVE:
address += self.relative_base
else:
assert mode == ParameterMode.POSITION # Sanity check
assert address >= 0 # Sanity check
self._fill_to_addres(address)
self.memory[address] = value
def _do_addition(self, instr: Instruction) -> None:
lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
dest = self.memory[instr.address + 3]
self._set_value(instr.p3_mode, dest, lhs + rhs)
self.rip += 4 # Length of the instruction
def _do_multiplication(self, instr: Instruction) -> None:
lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
dest = self.memory[instr.address + 3]
self._set_value(instr.p3_mode, dest, lhs * rhs)
self.rip += 4 # Length of the instruction
def _do_input(self, instr: Instruction) -> None:
if len(self.input_list) == 0:
raise InputInterrupt # No input, halt until an input is provided
value = int(self.input_list.pop(0))
param = self.memory[instr.address + 1]
self._set_value(instr.p1_mode, param, value)
self.rip += 2 # Length of the instruction
def _do_output(self, instr: Instruction) -> None:
value = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
self.output_list.append(value)
self.rip += 2 # Length of the instruction
raise OutputInterrupt # Alert that we got an output to give
def _do_jump_if_true(self, instr: Instruction) -> None:
cond = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
value = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
if cond != 0:
self.rip = value
else:
self.rip += 3 # Length of the instruction
def _do_jump_if_false(self, instr: Instruction) -> None:
cond = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
value = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
if cond == 0:
self.rip = value
else:
self.rip += 3 # Length of the instruction
def _do_less_than(self, instr: Instruction) -> None:
lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
dest = self.memory[instr.address + 3]
self._set_value(instr.p3_mode, dest, 1 if lhs < rhs else 0)
self.rip += 4 # Length of the instruction
def _do_equal_to(self, instr: Instruction) -> None:
lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
dest = self.memory[instr.address + 3]
self._set_value(instr.p3_mode, dest, 1 if lhs == rhs else 0)
self.rip += 4 # Length of the instruction
def _do_change_relative_base(self, instr: Instruction) -> None:
value = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
self.relative_base += value
self.rip += 2 # Length of the instruction
class Position(NamedTuple):
x: int
y: int
class Direction(Enum):
NORTH = auto()
WEST = auto()
SOUTH = auto()
EAST = auto()
DIRECTIONS = [d for d in Direction]
ARROW_DIRECTION = {
"^": Direction.NORTH,
"v": Direction.SOUTH,
"<": Direction.WEST,
">": Direction.EAST,
}
DIRECTION_OFFSET = {
Direction.NORTH: (-1, 0),
Direction.SOUTH: (1, 0),
Direction.WEST: (0, -1),
Direction.EAST: (0, 1),
}
def turn(d: Direction, turn: str) -> Direction:
def turn_left() -> Direction:
return DIRECTIONS[(DIRECTIONS.index(d) + 1) % len(DIRECTIONS)]
def turn_right() -> Direction:
return DIRECTIONS[DIRECTIONS.index(d) - 1]
if turn == "L":
return turn_left()
elif turn == "R":
return turn_right()
assert False # Sanity check
def find_arrow(mapped_view: List[List[str]]) -> Position:
for x in range(len(mapped_view)):
for y in range(len(mapped_view[0])):
if mapped_view[x][y] in ARROW_DIRECTION:
return Position(x, y)
assert False # Sanity check
def get_path(mapped_view: List[List[str]]) -> List[str]:
pos = find_arrow(mapped_view)
def pos_is_valid(p: Position) -> bool:
return 0 <= p.x < len(mapped_view) and 0 <= p.y < len(mapped_view[0])
def pos_is_scaffold(p: Position) -> bool:
return pos_is_valid(p) and mapped_view[p.x][p.y] != "."
direction = ARROW_DIRECTION[mapped_view[pos.x][pos.y]]
ans: List[str] = []
def advance_until_stopped(turn_string: str) -> bool:
nonlocal pos
nonlocal direction
d = turn(direction, turn_string)
offset = DIRECTION_OFFSET[d]
neighbor = Position(*(a + b for a, b in zip(pos, offset)))
tot = 0
while pos_is_scaffold(neighbor):
tot += 1
mapped_view[pos.x][pos.y] = "@"
pos = neighbor
neighbor = Position(*(a + b for a, b in zip(pos, offset)))
if tot == 0:
return False
direction = d
ans.append(turn_string)
ans.append(str(tot))
return True
has_no_neighbors = False
while not has_no_neighbors:
for turn_string in ("L", "R"):
if advance_until_stopped(turn_string):
break
else:
has_no_neighbors = True
return ans
def sequitur_algorithm(path: str) -> None:
# FIXME: seems like a good candidate for compression
pass
def main() -> None:
memory = [int(n) for n in sys.stdin.read().split(",")]
camera = Computer(deepcopy(memory))
camera.run_no_output_interrupt()
view = "".join(chr(c) for c in camera.output_list)
mapped_view = [[c for c in line] for line in view.split("\n") if line != ""]
path = get_path(mapped_view)
print(path)
# I didn't want to write the compression algorithm when I could just use Vim
# The answere is A,B,B,A,C,A,A,C,B,C
# A: R,8,L,12,R,8
# B: R,12,L,8,R,10
# C: R,8,L,8,L,8,R,8,R,10
ans = "A,B,B,A,C,A,A,C,B,C"
A = "R,8,L,12,R,8"
B = "R,12,L,8,R,10"
C = "R,8,L,8,L,8,R,8,R,10"
assert len(ans) <= 20 # Sanity check
assert len(A) <= 20 # Sanity check
assert len(B) <= 20 # Sanity check
assert len(C) <= 20 # Sanity check
memory[0] = 2 # Wake up the robot
robot = Computer(memory)
for c in ans:
robot.input_list.append(ord(c))
robot.input_list.append(ord("\n"))
for c in A:
robot.input_list.append(ord(c))
robot.input_list.append(ord("\n"))
for c in B:
robot.input_list.append(ord(c))
robot.input_list.append(ord("\n"))
for c in C:
robot.input_list.append(ord(c))
robot.input_list.append(ord("\n"))
for c in "n\n": # Do not output the video feed
robot.input_list.append(ord(c))
robot.run_no_output_interrupt()
print(robot.output_list.pop())
if __name__ == "__main__":
main()