day_5

# Read input

list_of_boarding_passes = open('input.txt').read().split('\n')


def split_list(local_char, local_list):
    local_length = len(local_list)
    local_middle_index = local_length // 2
    local_lower_half = local_list[:local_middle_index]
    local_upper_half = local_list[local_middle_index:]
    if local_char in ('FL'):
        return(local_lower_half)
    elif local_char in ('BR'):
        return(local_upper_half)

# Part One

seat_id_list = []

for boarding_pass in list_of_boarding_passes:
    seat = list(range(128))
    column = list(range(8))
    for b in boarding_pass:
        if b in ('FB'):
            seat = split_list(b, seat)
        if b in ('RL'):
            column = split_list(b, column)
    seat_id = (seat[0] * 8 + column[0])
    seat_id_list.append(seat_id)
    
print('the highest seat id: ', max(seat_id_list))

# Part Two

seat_id_list.sort()

for seat_id_lower, seat_id_upper in zip(seat_id_list[:-1], seat_id_list[1:]):
    if seat_id_upper - seat_id_lower == 2:
        print('your seat id: ', (seat_id_lower + 1))