path: root/day7.py

#!/usr/bin/env python

from functools import cache
from collections import defaultdict
import operator

ops = {
    'EQ': lambda x: x,
    'NOT': lambda x: ~x & 0xffff,
    'AND': operator.iand,
    'OR': operator.ior,
    'RSHIFT': operator.rshift,
    'LSHIFT': operator.lshift
}

wires = defaultdict(list)
with open('day7.txt') as data:
    for line in data:
        calc, target = line.strip().split(' -> ')
        calc = calc.split()
        if len(calc) == 1:
            wires[target] = ('EQ', calc[0])
        elif len(calc) == 2:
            wires[target] = (calc[0], calc[1])
        else:
            wires[target] = (calc[1], calc[0], calc[2])

@cache
def get_value(key):
    try:
        return int(key)
    except ValueError:
        pass

    op, *value = wires[key]

    if len(value) == 1:
        return ops[op](get_value(value[0]))
    else:
        return ops[op](get_value(value[0]), get_value(value[1]))

# part 1
print(get_value('a'))

# part 2
get_value.cache_clear()

wires['b'] = ('EQ', 3176)
print(get_value('a'))