def dijkstra(start, end, board):
Node = namedtuple("Node", ["pos", "d", "p"])
seen = {}
q = PriorityQueue()
q.add(Node(start, 0, None), 0)
while (len(q) > 0):
cur = q.pop()
if (cur.pos in seen):
continue
seen[cur.pos] = {'d': cur.d, 'p': cur.p}
#Terminate early if we find the end
if (cur.pos == end):
break
neighbors = [
tile for tile in adjacent_positions(cur.pos)
if (tile == end or tile_is_empty(tile, board))
]
for tile in neighbors:
q.add(Node(tile, cur.d + 1, cur.pos), cur.d + 1)
if (end not in seen):
return None
path = []
current = end
while (current is not None):
path.insert(0, current)
current = seen[current]['p']
return path
def a_star(start, end, board):
Node = namedtuple("Node", ["pos", "d", "prev"])
seen = {}
q = PriorityQueue()
q.add(Node(start, 0, None), manhattan(start, end))
while (len(q) > 0):
current = q.pop()
if (current.pos in seen):
continue
seen[current.pos] = current.prev
if (current.pos == end):
break
neighbors = [
tile for tile in adjacent_positions(current.pos)
if (tile == end or tile_is_empty(tile, board))
]
for neighbor in neighbors:
q.add(Node(neighbor, current.d + 1, current.pos),
current.d + 1 + manhattan(neighbor, end))
if (end not in seen):
return None
path = []
current = end
while (current is not None):
path.insert(0, current)
current = seen[current]
return path
class test_avltree(TestCase):
def setUp(self):
self.priorityqueue = PriorityQueue()
self.priorityqueue.add(5, 5)
self.priorityqueue.add(4, 4)
self.priorityqueue.add(3, 3)
self.priorityqueue.add(2, 2)
self.priorityqueue.add(1, 1)
def test_min(self):
self.assertEqual(self.priorityqueue.min()[1], 1)
