advent-of-code/src/holt59/aoc/2015/day7.py

import logging
import operator
import os
import sys
from typing import Callable

VERBOSE = os.getenv("AOC_VERBOSE") == "True"
logging.basicConfig(level=logging.INFO if VERBOSE else logging.WARNING)

OPERATORS = {
    "AND": operator.and_,
    "OR": operator.or_,
    "LSHIFT": operator.lshift,
    "RSHIFT": operator.rshift,
}

ValueGetter = Callable[[dict[str, int]], int]
Signals = dict[
    str,
    tuple[
        tuple[str, str],
        tuple[ValueGetter, ValueGetter],
        Callable[[int, int], int],
    ],
]


def zero_op(_a: int, _b: int) -> int:
    return 0


def value_of(key: str) -> tuple[str, Callable[[dict[str, int]], int]]:
    try:
        return "", lambda _p, _v=int(key): _v
    except ValueError:
        return key, lambda values: values[key]


lines = sys.stdin.read().splitlines()

signals: Signals = {}
values: dict[str, int] = {"": 0}

for line in lines:
    command, signal = line.split(" -> ")

    if command.startswith("NOT"):
        name = command.split(" ")[1]
        signals[signal] = (
            (name, ""),
            (lambda values, _n=name: values[_n], lambda _v: 0),
            lambda a, _b: ~a,
        )

    elif not any(command.find(name) >= 0 for name in OPERATORS):
        try:
            values[signal] = int(command)
        except ValueError:
            signals[signal] = (
                (command, ""),
                (lambda values, _c=command: values[_c], lambda _v: 0),
                lambda a, _b: a,
            )

    else:
        op: Callable[[int, int], int] = zero_op
        lhs_s, rhs_s = "", ""

        for name in OPERATORS:
            if command.find(name) >= 0:
                op = OPERATORS[name]
                lhs_s, rhs_s = command.split(f" {name} ")
                break

        lhs_s, lhs_fn = value_of(lhs_s)
        rhs_s, rhs_fn = value_of(rhs_s)

        signals[signal] = ((lhs_s, rhs_s), (lhs_fn, rhs_fn), op)


def process(
    signals: Signals,
    values: dict[str, int],
) -> dict[str, int]:
    while signals:
        signal = next(s for s in signals if all(p in values for p in signals[s][0]))
        _, deps, command = signals[signal]
        values[signal] = command(deps[0](values), deps[1](values)) % 65536
        del signals[signal]

    return values


values_1 = process(signals.copy(), values.copy())
logging.info("\n" + "\n".join(f"{k}: {values_1[k]}" for k in sorted(values_1)))
answer_1 = values_1["a"]
print(f"answer 1 is {answer_1}")

values_2 = process(signals.copy(), values | {"b": values_1["a"]})
answer_2 = values_2["a"]
print(f"answer 2 is {answer_2}")