1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
import collections
import heapq as heap
import sys
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:
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)
def avail(map, start, items, dead, ignore=set(), ignore_except=set()):
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 ignore and n not in ignore_except:
continue
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
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, map_doors):
start_paths[("@", map_keys[a[1]])] = a[0]
def v_from_k(items: dict, item: str):
for k,v in items.items():
if item == v:
return k
return None
def pos_from_item(item, keys, doors):
return v_from_k((keys if item.islower() else doors), item)
def avail_keys(map, keys, doors, graph, start, keys_left, unlocked_doors):
visited = set()
avail = []
h = []
heap.heappush(h, (0, start))
while len(h) > 0:
dist, cur_key = heap.heappop(h)
if cur_key != start and cur_key.islower() and cur_key in keys_left:
avail.append((dist, cur_key))
continue
for n in graph[cur_key]:
if n[0].isupper() and n[0] not in unlocked_doors:
continue
if n[0] in visited:
continue
visited.add(n[0])
heap.heappush(h, (dist + n[1], n[0]))
return avail
h = []
for path, dist in start_paths.items():
cur = path[1]
keys_left = set(map_keys.values()).copy()
keys_left.remove(cur)
unlocked = set()
unlocked.add(cur.upper())
key_path = [cur]
heap.heappush(h, (dist, cur, keys_left, unlocked, key_path))
best = len(map_keys)
seen = set()
while True:
dist, key, keys_left, unlocked, key_path = heap.heappop(h)
#print("\nnode", dist, key, keys_left, unlocked, key_path)
if (frozenset(key_path), key) in seen:
#print("skipping", key_path, key)
continue
seen.add((frozenset(key_path), key))
if len(keys_left) == 0:
print(dist, "with path", key_path)
sys.exit()
if len(keys_left) < best:
best = len(keys_left)
print("best", len(unlocked), "with dist", dist, "and path", key_path)
for new_dist, new_key in avail_keys(map, map_keys, map_doors, graph, key, keys_left, unlocked):
#print("edge", new_dist, new_key)
new_keys_left = keys_left.copy()
new_keys_left.remove(new_key)
new_unlocked = unlocked.copy()
new_unlocked.add(new_key.upper())
new_key_path = key_path.copy()
new_key_path.append(new_key)
#print("adding", dist+new_dist, new_key, new_keys_left, new_unlocked, new_key_path)
heap.heappush(h, (dist + new_dist, new_key, new_keys_left, new_unlocked, new_key_path))
|
