├── .gitgnore
├── README.md
└── main.py


/.gitgnore:
--------------------------------------------------------------------------------
1 | .idea/
2 | .DS_Store
3 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 | # Solver for http://www.dogbunnypuzzle.com/
2 | 
3 | Run `python3 main.py`
4 | 


--------------------------------------------------------------------------------
/main.py:
--------------------------------------------------------------------------------
  1 | START_NODES = {
  2 |     "house": ["bunny"],
  3 |     "bone": [],
  4 |     "boat": ["bunny"],
  5 |     "flower": [],
  6 |     "well": [],
  7 |     "carrot": [],
  8 |     "tree": ["dog"]
  9 | }
 10 | 
 11 | TARGET_NODES = {
 12 |     "house": [],
 13 |     "bone": ["dog"],
 14 |     "boat": [],
 15 |     "flower": [],
 16 |     "well": [],
 17 |     "carrot": ["bunny", "bunny"],
 18 |     "tree": []
 19 | }
 20 | # From, To, MustBeOn, MustBeOff
 21 | EDGES = [
 22 |     ("bone", "boat", (), ()),
 23 |     ("bone", "house", ("carrot",), ()),
 24 |     ("house", "bone", ("carrot",), ()),
 25 |     ("house", "boat", ("tree",), ()),
 26 |     ("house", "tree", ("bone", "flower"), ()),
 27 |     ("tree", "house", ("bone", "flower"), ()),
 28 |     ("tree", "well", (), ()),
 29 |     ("carrot", "tree", (), ()),
 30 |     ("carrot", "well", (), ("bone",)),
 31 |     ("well", "carrot", (), ("bone",)),
 32 |     ("well", "tree", (), ()),
 33 |     ("well", "flower", (), ()),
 34 |     ("flower", "well", (), ()),
 35 |     ("flower", "boat", (), ()),
 36 |     ("boat", "house", ("tree",), ()),
 37 | ]
 38 | 
 39 | EDGES_OF_NODE = {node: [edge[1:] for edge in EDGES if edge[0] == node] for node in START_NODES}
 40 | 
 41 | 
 42 | class DogBunnyGraph:
 43 |     def __init__(self, nodes=None, description=""):
 44 |         self.nodes = START_NODES if nodes is None else nodes
 45 |         self.description = description
 46 | 
 47 |     def __str__(self):
 48 |         return str({node: self.nodes[node] for node in sorted(self.nodes)})
 49 | 
 50 |     def __hash__(self):
 51 |         return str(self)
 52 | 
 53 |     def copy(self):
 54 |         nodes = {node: pieces[:] for node, pieces in self.nodes.items()}
 55 |         return DogBunnyGraph(nodes)
 56 | 
 57 |     def neighbors(self):
 58 |         neighbors = []
 59 |         for (node, contents) in self.nodes.items():
 60 |             if not len(contents):
 61 |                 continue  # Nothing to move
 62 |             for piece in set(contents):
 63 |                 for (to_node, on_constraint, off_constraint) in EDGES_OF_NODE[node]:
 64 |                     constraints_okay = True
 65 |                     for must_be_on in on_constraint:
 66 |                         if not len(self.nodes[must_be_on]):
 67 |                             constraints_okay = False
 68 |                             break
 69 |                     for must_be_off in off_constraint:
 70 |                         if len(self.nodes[must_be_off]):
 71 |                             constraints_okay = False
 72 |                             break
 73 | 
 74 |                     if not constraints_okay:
 75 |                         continue
 76 | 
 77 |                     next_nodes = {node: pieces[:] for node, pieces in self.nodes.items()}
 78 |                     next_nodes[node].remove(piece)
 79 |                     next_nodes[to_node].append(piece)
 80 |                     next_nodes[to_node].sort()
 81 | 
 82 |                     neighbors.append(DogBunnyGraph(next_nodes, f"Move {piece} from {node} --> {to_node}"))
 83 | 
 84 |         return neighbors
 85 | 
 86 | 
 87 | from collections import deque
 88 | 
 89 | 
 90 | def search():
 91 |     init = DogBunnyGraph(START_NODES)
 92 |     target = DogBunnyGraph(TARGET_NODES)
 93 |     target_str = str(target)
 94 |     q = deque([(init, str(init), [])])
 95 |     seen = set()
 96 |     while len(q):
 97 |         (graph, graph_str, history) = q.popleft()
 98 |         if graph_str in seen:
 99 |             continue
100 |         seen.add(graph_str)
101 |         if graph_str == target_str:
102 |             print("Found! ", len(history))
103 |             for step in history:
104 |                 print(step)
105 |             print(graph.description)
106 | 
107 |             break
108 |         for n in graph.neighbors():
109 |             q.append((n, str(n), history + [graph.description]))
110 | 
111 | 
112 | if __name__ == '__main__':
113 |     search()
114 | 


--------------------------------------------------------------------------------