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import collections
import heapq as heap
def neighbours(p):
return [(p[0]+1, p[1]), (p[0]-1, p[1]), \
(p[0], p[1]+1), (p[0], p[1]-1)]
def draw(map, pos=None, keys={}, doors={}, path={}, visited={}, dead=set()) -> str:
min_x=max_x=min_y=max_y = 0
for p in map:
min_x = min(p[0], min_x)
max_x = max(p[0], max_x)
min_y = min(p[1], min_y)
max_y = max(p[1], max_y)
s = ""
for y in range(min_y-1, max_y+2):
s += "\n"
for x in range(min_x-1, max_x+2):
point = (x, y)
if pos is not None and point == pos:
s += "@"
elif point in keys:
s += keys[point]
elif point in doors:
s += doors[point]
elif point in path:
s += "\u2591"
elif point in visited:
s += "."
elif point in dead:
s += "X"
elif point in map:
if map[point] == "#":
s += "\u2588"
else:
s += " "
else:
s += "."
return s
def path(start: tuple, end:tuple, board:dict, keys={}, doors={}, draw_search=False):
''' Find the shortest path between two points '''
if start == end:
return collections.deque()
visited = set()
h = []
heap.heappush(h, (0, start, collections.deque()))
while True:
if len(h) == 0:
print(visited)
return
cur = heap.heappop(h)
for n in neighbours(cur[1]):
if n == end:
cur[2].append(n)
if draw_search:
print(draw(board, path=cur[2], visited=visited))
return cur[2]
if n in visited or n not in board or board[n] == "#":
continue
if n in keys or n in doors:
continue
new_path = collections.deque(cur[2])
new_path.append(n)
visited.add(n)
heap.heappush(h, (cur[0] + 1, n, new_path))
if draw_search:
time.sleep(0.0075)
print(draw(board, keys=keys, doors=doors, path=new_path, visited=visited))
print(end)
print(n)
def avail(map, start, items, dead):
visited = set()
avail = []
q = collections.deque()
q.append((0, start))
while len(q) > 0:
cur = q.popleft()
dist = cur[0]
pos = cur[1]
if pos in items and pos != start:
avail.append((dist, pos, items[pos]))
continue
for n in neighbours(pos):
if n in map and map[n] == "#":
continue
if n in dead:
continue
if n in visited:
continue
visited.add(n)
q.append((dist+1, n))
return avail
def seen_before(keys, paths):
for path in paths:
if set(keys) == set(path) and keys[-1] == path[-1]:
return True
return False
input = open("../input/18", "r").readlines()
map = {}
map_keys = {}
map_doors = {}
map_keys_doors = {}
walls = set()
tiles = set()
for y in range(len(input)):
for x in range(len(input[y].strip())):
c = input[y][x]
p = (x,y)
if c == "@":
start = p
map[p] = "."
elif c.isalpha():
if c.isupper():
map_doors[p] = c
else:
map_keys[p] = c
map[p] = "."
elif c == "#":
walls.add(p)
map[p] = c
elif c == ".":
tiles.add(p)
map[p] = c
map_keys_doors.update(map_keys)
map_keys_doors.update(map_doors)
dead = set()
for _ in range(10):
ends = set()
intersections = set()
for tile in tiles:
num_walls = 0
for n in neighbours(tile):
if n in walls or n in dead:
num_walls += 1
if num_walls == 3:
ends.add(tile)
elif num_walls < 2:
intersections.add(tile)
for end in ends:
cur = end
while cur not in intersections and cur not in map_keys and cur not in map_doors:
dead.add(cur)
if cur in tiles:
tiles.remove(cur)
for n in neighbours(cur):
if n not in walls and n not in dead:
cur = n
break
paths = {} # every path available between a door and a key
start_paths = {} # every path available from the starting point
graph = {} # {node: [children as tuples with name and distance]}
for ent, s in map_keys_doors.items():
for a in avail(map, ent, map_keys_doors, dead):
paths[(s, a[2])] = a[0]
graph[s] = graph.get(s, []) + [(a[2], a[0])]
for a in avail(map, start, map_keys, dead):
start_paths[("@", map_keys[a[1]])] = a[0]
h = []
for path, dist in start_paths.items():
cur = path[1]
keys = [path[1]]
unlocked = set()
unlocked.add(cur.upper())
heap.heappush(h, (dist, cur, keys, unlocked))
m = 0
seen = []
while True:
print(len(h))
candidate = heap.heappop(h)
dist = candidate[0]
cur = candidate[1]
keys = candidate[2]
unlocked = candidate[3]
# if seen_before
if seen_before(keys, seen):
continue
seen.append(keys)
if len(unlocked) > m:
m = len(unlocked)
print(m, keys)
if len(unlocked) == len(map_doors):
break
for n in graph[cur]:
if n[0].isupper() and n[0] not in unlocked:
continue
keys = keys.copy()
unlocked = unlocked.copy()
if n[0].islower():
keys.append(n[0])
unlocked.add(n[0].upper())
heap.heappush(h, (dist+n[1], n[0], keys, unlocked))
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