AOC 2020 day 5

aoc_2020_day5.py

with open('input.txt') as f:
    raw = f.read()

def row(code, lower=0, upper=127):
    if len(code) == 3: return lower

    if code[0] == 'F':
        return row(code[1:], lower, (lower + upper) // 2)
    if code[0] == 'B':
        return row(code[1:], (lower + upper) // 2 + 1, upper)


def column(code, lower=0, upper=7):
    if len(code) > 3:
        return column(code[-3:], lower, upper)
    if not code: 
        return lower

    if code[0] == 'L':
        return column(code[1:], lower, (lower + upper) // 2)
    if code[0] == 'R':
        return column(code[1:], (lower + upper) // 2 + 1, upper)


def seat_id(code):
    r = row(code)
    c = column(code)
    return r * 8 + c

all_seats = {seat_id(i) for i in raw.split()}
print('part one: ', max(all_seats))

for i in range(min(all_seats), max(all_seats)):
    try:
        all_seats.remove(i)
    except KeyError:
        print('your seat: ', i)