ass-day-11-2.py

import copy

# Generate current state for each seat

def pretty_print(matrix):
    print('\n'.join([' '.join([str(cell) for cell in row]) for row in matrix]))
    print("\n------------------------------------------\n")

def get_hash(seat_plan):
    hash = ''
    for row in seat_plan:
        hash += ''.join(row)
    return hash

def is_valid_position(idxr, idxs, seat_plan):
    return \
        0 <= idxr < len(seat_plan) \
        and 0 <= idxs < len(seat_plan[0])


def find_first_chair_in_direction(idxr, idxs,direction_r, direction_s, current_state ):
    next_r = idxr + direction_r
    next_s = idxs + direction_s

    while is_valid_position(next_r, next_s, current_state):
        if current_state[next_r][next_s] in ('L', '#'):
            return current_state[next_r][next_s]

        next_r = next_r + direction_r
        next_s = next_s + direction_s

    return None


def get_surroundings(idxr, idxs, current_state):
    surrounding_seats = []

    for y in range(-1, 2):
        for x in range(-1, 2):
            if not (x==0 and y==0):
                first_visible_seat = find_first_chair_in_direction(idxr, idxs, y, x, current_state)
                surrounding_seats.append(first_visible_seat)
                # print(f"({y},{x})")
    return surrounding_seats


def get_new_seat_occupation(idxr, idxs, current_state):
    surrounding_seats = get_surroundings(idxr, idxs, current_state)
    state = current_state[idxr][idxs]
    # print(f"get_new_seat_occupation({idxr},{idxs}), current_state={state}, surrounding_seats={surrounding_seats}")

    if state == 'L' and not '#' in surrounding_seats:
        return '#'
    elif state == '#':
        if sum(1 for x in surrounding_seats if x == '#') >=5:
            return 'L'

    return state


def get_next_state(current_state):
    next_state = copy.deepcopy(current_state)

    for idxr, row in enumerate(current_state):
        for idxs, seat in enumerate(row):
            next_state[idxr][idxs] = get_new_seat_occupation(idxr, idxs, current_state)

    return next_state

# Read input
f = open("ass-day-11-input.txt", "r")
lines = f.read().split("\n")
seat_plan = [list(line) for line in lines]

# Repeat
current_state = seat_plan
new_state = get_next_state(seat_plan)

iteration =0
while get_hash(current_state) != get_hash(new_state):
    # print(f"Iteration: {iteration}")
    current_state = new_state
    new_state = get_next_state(current_state)
    iteration +=1


print(f"Done.Iterated {iteration} times. Occupied seats {sum(1 for x in get_hash(new_state) if x == '#')}")
pretty_print(new_state)