day08.py

from aoc import get_input

instructions = get_input(day=8)


def parse(instructions):
    parsed = []
    for instruction in instructions:
        op, value = instruction.split()
        parsed.append([op, int(value)])
    return parsed


def run(instructions):
    i = 0
    acc = 0
    executed = set()
    while i not in executed and 0 <= i < len(instructions):
        executed.add(i)

        op, value = instructions[i]

        if op == 'nop':
            i += 1
        elif op == 'acc':
            acc += value
            i += 1
        elif op == 'jmp':
            i += value
        else:
            raise ValueError

    return i, acc


# 8-1
i, acc = run(parse(instructions))
print(acc)


# 8-2
mapping = {'nop': 'jmp',
           'jmp': 'nop'}
def perturbed(original):
    for i, (op, value) in enumerate(original):
        if op in mapping:
            new = original[:]
            new[i] = (mapping[op], value)
            yield new

for instructions in perturbed(parse(instructions)):
    i, acc = run(instructions)
    if i == len(instructions):
        print(acc)
        break