advent-of-code-2019/day7/py/main.py

221 lines
8.4 KiB
Python

import sys
import itertools
from typing import List, Tuple, Optional
# Halt indicates that the assembled program should terminate
class Halt(Exception):
pass
# Operation represents an operation that the intcode computer should do
class Operation:
OPCODE_TERMINATE = 99
OPCODE_ADD = 1
OPCODE_MULTIPLY = 2
OPCODE_INPUT = 3
OPCODE_OUTPUT = 4
OPCODE_JUMP_IF_TRUE = 5
OPCODE_JUMP_IF_FALSE = 6
OPCODE_LESS_THAN = 7
OPCODE_EQUALS = 8
MODE_POSITION = 0
MODE_IMMEDIATE = 1
ALL_OPCODES = (OPCODE_TERMINATE, OPCODE_ADD, OPCODE_MULTIPLY, OPCODE_INPUT, OPCODE_OUTPUT,
OPCODE_JUMP_IF_TRUE, OPCODE_JUMP_IF_FALSE, OPCODE_LESS_THAN, OPCODE_EQUALS)
def __init__(self, instruction: int):
# The opcode is the first two digits of the number, the rest are parameter modes
self.opcode: int = instruction % 100
if self.opcode not in Operation.ALL_OPCODES:
raise ValueError(f"Bad opcode: {self.opcode}")
self.modes: Tuple[int, ...] = self._extract_parameter_modes(instruction//100)
self.output = None
def _extract_parameter_modes(self, raw_modes) -> Tuple[int, ...]:
PARAMETER_COUNTS = {
Operation.OPCODE_TERMINATE: 0,
Operation.OPCODE_ADD: 3,
Operation.OPCODE_MULTIPLY: 3,
Operation.OPCODE_INPUT: 1,
Operation.OPCODE_OUTPUT: 1,
Operation.OPCODE_JUMP_IF_TRUE: 2,
Operation.OPCODE_JUMP_IF_FALSE: 2,
Operation.OPCODE_LESS_THAN: 3,
Operation.OPCODE_EQUALS: 3,
}
# Opcodes that write to memory as their last parameter
MEMORY_OPCODES = (Operation.OPCODE_ADD, Operation.OPCODE_MULTIPLY, Operation.OPCODE_INPUT,
Operation.OPCODE_LESS_THAN, Operation.OPCODE_EQUALS)
num_parameters = PARAMETER_COUNTS[self.opcode]
modes = [Operation.MODE_POSITION for i in range(num_parameters)]
mode_str = str(raw_modes)
# Iterate over the modes digits backwards, assigning them to the parameter list until we exhaust the modes
# The rest must be leading zeroes
for mode_index, digit in zip(range(num_parameters), reversed(mode_str)):
modes[mode_index] = int(digit)
# The last argument (the address parameter) must always be in immediate mode
# The problem statement is misleading in this regard. You do NOT want to get an address to store the value
# at from another address.
if self.opcode in MEMORY_OPCODES:
modes[-1] = Operation.MODE_IMMEDIATE
return tuple(modes)
# Run the given operation, starting at the given instruction pointer
# Returns the address that the instruction pointer should become, followed by the output of the operation, if any
def run(self, memory: List[int], instruction_pointer: int, program_input: Optional[int] = None) -> Tuple[int, Optional[int]]:
OPERATION_FUNCS = {
# nop for terminate
Operation.OPCODE_TERMINATE: Operation.terminate,
Operation.OPCODE_ADD: Operation.add,
Operation.OPCODE_MULTIPLY: Operation.multiply,
Operation.OPCODE_INPUT: Operation.input,
Operation.OPCODE_OUTPUT: Operation.output,
Operation.OPCODE_JUMP_IF_TRUE: Operation.jump_if_true,
Operation.OPCODE_JUMP_IF_FALSE: Operation.jump_if_false,
Operation.OPCODE_LESS_THAN: Operation.less_than,
Operation.OPCODE_EQUALS: Operation.equals
}
# Reset the output of a previous run
self.output = None
args = []
for i, mode in enumerate(self.modes):
# Add 1 to move past the opcode itself
pointer = instruction_pointer + i + 1
arg = memory[pointer]
if mode == Operation.MODE_POSITION:
arg = memory[arg]
elif mode != Operation.MODE_IMMEDIATE:
raise ValueError(f"Invalid parameter mode {mode}")
args.append(arg)
func = OPERATION_FUNCS[self.opcode]
if program_input is None:
jump_addr = func(self, memory, *args)
else:
jump_addr = func(self, memory, program_input, *args)
if jump_addr is not None:
return jump_addr, self.output
return instruction_pointer + len(self.modes) + 1, self.output
def terminate(self, memory: List[int]) -> None:
raise Halt("catch fire")
def add(self, memory: List[int], a: int, b: int, loc: int) -> None:
memory[loc] = a + b
def multiply(self, memory: List[int], a: int, b: int, loc: int) -> None:
memory[loc] = a * b
def input(self, memory: List[int], program_input: int, loc: int) -> None:
memory[loc] = program_input
def output(self, memory: List[int], value: int) -> None:
self.output = value
print("OUTPUT:", value)
def jump_if_true(self, memory: List[int], test_value: int, new_instruction_pointer: int) -> Optional[int]:
return new_instruction_pointer if test_value != 0 else None
def jump_if_false(self, memory: List[int], test_value: int, new_instruction_pointer: int) -> Optional[int]:
return new_instruction_pointer if test_value == 0 else None
def less_than(self, memory: List[int], a: int, b: int, loc: int):
memory[loc] = int(a < b)
def equals(self, memory: List[int], a: int, b: int, loc: int):
memory[loc] = int(a == b)
# Executes the program, returning the instruction pointer to continue at (if the program paused) and a list of all
# outputs that occurred during the program's execution
def execute_program(memory: List[int], program_inputs: List[int], initial_instruction_pointer: int = 0) -> (Optional[int], List[int]):
i = initial_instruction_pointer
input_cursor = 0
outputs = []
while i < len(memory):
operation = Operation(memory[i])
program_input = None
# If we're looking for input
if operation.opcode == Operation.OPCODE_INPUT:
# If we are out of input, don't fail out, but rather just pause execution
if input_cursor >= len(program_inputs):
return i, outputs
program_input = program_inputs[input_cursor]
input_cursor += 1
try:
i, output = operation.run(memory, i, program_input)
except Halt:
break
if output is not None:
outputs.append(output)
# The program is finished, and we are saying there is no instruction pointer
return None, outputs
def part1(inputs: List[int]) -> int:
possible_phases = list(range(5))
max_output = 0
for permutation in itertools.permutations(possible_phases):
last_output = 0
for phase in permutation:
_, outputs = execute_program(inputs[:], [phase, last_output])
last_output = outputs[-1]
if last_output > max_output:
max_output = last_output
return max_output
def part2(inputs: List[int]) -> int:
max_output = 0
for phase_permutation in itertools.permutations(range(5, 10)):
last_output = 0
amplifiers = [{"memory": inputs[:], "next_ip": 0} for i in range(5)]
# Go over all of the amplifiers and the phase permutation item one by one
for amplifier, phase in itertools.cycle(zip(amplifiers, phase_permutation)):
next_input = [last_output]
# If the program is not currently running, add the phase as the first input
# Passing both inputs allows us to have an output from this step
if amplifier["next_ip"] == 0:
next_input.insert(0, phase)
last_ip, outputs = execute_program(amplifier["memory"], next_input, amplifier["next_ip"])
amplifier["next_ip"] = last_ip
# We are sure we will only get one output for this phase
last_output = outputs[-1]
# If none of the programs are running, stop
if all(amplifier["next_ip"] is None for amplifier in amplifiers):
break
if last_output > max_output:
max_output = last_output
return max_output
if __name__ == "__main__":
if len(sys.argv) != 2:
print("Usage: ./main.py in_file")
sys.exit(1)
with open(sys.argv[1]) as f:
inputs = [int(item) for item in f.read().rstrip().split(",")]
print("PART 1")
print(part1(inputs))
print("PART 2")
print(part2(inputs))