>>103562246
nah, it's totally random. it's not the neat grid maze of the official input but just a random self-avoiding dfs. here is an image of a smaller sample.
import random
from collections import deque, defaultdict
from itertools import product
visited = {(0, 0)}
frontier = deque([(0, 0)])
dirs_ = [(-1, 0), (0, 1), (1, 0), (0, -1)]
SIZE = 100
indices = defaultdict(int)
def get_rng_list():
l = dirs_.copy()
random.shuffle(l)
return l
explore = defaultdict(get_rng_list)
while frontier:
x, y = frontier[-1]
i = indices[(x, y)]
if i > 3:
frontier.pop()
continue
random.shuffle(dirs_)
dx, dy = explore[(x, y)][i]
indices[(x, y)] += 1
nx, ny = x + dx, y + dy
if (nx, ny) not in visited:
if 0 <= nx < SIZE and 0 <= ny < SIZE:
is_valid = True
for ddx, ddy in product([-1, 0, 1], repeat=2):
if ddx == ddy == 0:
continue
if ddx * dx + ddy * dy < 0:
continue
is_valid &= (nx + ddx, ny + ddy) not in visited
if is_valid:
visited.add((nx, ny))
frontier.append((nx, ny))
all_coords = {*product(range(SIZE), range(SIZE))}
unvisited = [*(all_coords - visited)]
visited = [*visited]
random.shuffle(visited)
random.shuffle(unvisited)
print(len(unvisited))
coords = unvisited + visited
with open("/tmp/bigboy.txt", "w") as f:
for x, y in coords:
f.write("{},{}\n".format(x, y))
