def shd(node_1: BinaryTreeNode, node_2: BinaryTreeNode,
hd: Callable[[BinaryTreeNode, BinaryTreeNode], float]) -> float:
"""Structural Hamming distance (SHD)
:param node_1:
:param node_2:
:param hd:
:return:
"""
if node_1 is None or node_2 is None:
return 1
# first get arity of each node
arity_1 = 0
arity_2 = 0
if node_1.has_left_child():
arity_1 += 1
if node_1.has_right_child():
arity_1 += 1
if node_2.has_left_child():
arity_2 += 1
if node_2.has_right_child():
arity_2 += 1
if arity_1 != arity_2:
return 1
else:
if arity_1 == 0:
# both are leaves
return hd(node_1, node_2)
else:
m = arity_1
ham_dist = hd(node_1, node_2)
children_dist_sum = sum([
shd(node_1.left, node_2.left, hd),
shd(node_1.right, node_2.right, hd)
])
return (1 / (m + 1)) * (ham_dist + children_dist_sum)
class TestBinaryTreeNode(TestCase):
def setUp(self):
self.root_val = 'Parent Value'
self.root = BinaryTreeNode(self.root_val)
self.left_child_val = 42
self.right_child_val = 13
def test_has_left_child(self):
self.assertFalse(self.root.has_left_child())
self.root.add_right(self.right_child_val)
self.assertFalse(self.root.has_left_child())
self.root.add_left(self.left_child_val)
self.assertTrue(self.root.has_left_child())
def test_has_right_child(self):
self.assertFalse(self.root.has_right_child())
self.root.add_left(self.left_child_val)
self.assertFalse(self.root.has_right_child())
self.root.add_right(self.right_child_val)
self.assertTrue(self.root.has_right_child())
def test_has_parent(self):
self.assertFalse(self.root.has_parent())
right = self.root.add_right(self.right_child_val)
self.assertTrue(right.has_parent())
self.assertTrue(self.root.right.has_parent())
self.assertFalse(self.root.has_parent())
left = self.root.add_left(self.left_child_val)
self.assertTrue(left.has_parent())
self.assertTrue(self.root.left.has_parent())
self.assertFalse(self.root.has_parent())
def test_is_left_child(self):
self.assertRaises(AttributeError, self.root.is_left_child)
left = self.root.add_left(self.left_child_val)
self.assertTrue(left.is_left_child())
self.assertTrue(self.root.left.is_left_child())
right = self.root.add_right(self.right_child_val)
self.assertFalse(right.is_left_child())
self.assertFalse(self.root.right.is_left_child())
def test_is_right_child(self):
self.assertRaises(AttributeError, self.root.is_right_child)
left = self.root.add_left(self.left_child_val)
self.assertFalse(left.is_right_child())
self.assertFalse(self.root.left.is_right_child())
right = self.root.add_right(self.right_child_val)
self.assertTrue(right.is_right_child())
self.assertTrue(self.root.right.is_right_child())
def test_is_root(self):
self.assertTrue(self.root.is_root())
left = self.root.add_left(self.left_child_val)
self.assertFalse(left.is_root())
right = self.root.add_right(self.right_child_val)
self.assertFalse(right.is_root())
def test_is_leaf(self):
self.assertTrue(self.root.is_leaf())
left = self.root.add_left(self.left_child_val)
self.assertTrue(left.is_leaf())
self.assertFalse(self.root.is_leaf())
right = self.root.add_right(self.right_child_val)
self.assertTrue(right.is_leaf())
self.assertFalse(self.root.is_leaf())
def test_add_left(self):
result = self.root.add_left(self.left_child_val)
self.assertEqual(result.parent, self.root)
self.assertEqual(result.parent.value, self.root_val)
self.assertEqual(result.parent.left, result)
self.assertEqual(result.parent.left.value, self.left_child_val)
def test_add_right(self):
result = self.root.add_right(self.right_child_val)
self.assertEqual(result.parent, self.root)
self.assertEqual(result.parent.value, self.root_val)
self.assertEqual(result.parent.right, result)
self.assertEqual(result.parent.right.value, self.right_child_val)
def test_create_graph(self):
result = self.root.create_graph()
self.assertIsInstance(result, Digraph)
def test_height(self):
root = BinaryTreeNode('*')
self.assertEqual(root.height(), 1)
left = root.add_left(10)
self.assertEqual(root.height(), 2)
right = root.add_right(20)
self.assertEqual(root.height(), 2)
ll = left.add_left(40)
self.assertEqual(root.height(), 3)
left.add_right(50)
self.assertEqual(root.height(), 3)
right.add_left(60)
self.assertEqual(root.height(), 3)
right.add_right(70)
self.assertEqual(root.height(), 3)
ll.add_left(80)
self.assertEqual(root.height(), 4)
def test_contains(self):
root = BinaryTreeNode('*')
self.assertIn('*', root)
left = root.add_left(10)
self.assertIn('*', root)
self.assertIn(10, root)
self.assertIn(10, left)
self.assertIn(10, root.left)
right = root.add_right(20)
self.assertIn('*', root)
self.assertIn(20, right)
self.assertIn(20, right)
self.assertIn(20, root.right)
def test_iter(self):
root = BinaryTreeNode('*')
self.assertEqual(root.height(), 1)
left = root.add_left(10)
self.assertEqual(root.height(), 2)
right = root.add_right(20)
self.assertEqual(root.height(), 2)
ll = left.add_left(40)
self.assertEqual(root.height(), 3)
left.add_right(50)
self.assertEqual(root.height(), 3)
right.add_left(60)
self.assertEqual(root.height(), 3)
right.add_right(70)
self.assertEqual(root.height(), 3)
ll.add_left(80)
self.assertEqual(root.height(), 4)
result = []
for value in root:
self.assertIn(value, root)
result.append(value)
self.assertEqual(len(result), 8)
def test_len(self):
root = BinaryTreeNode('*')
self.assertEqual(len(root), 1)
left = root.add_left(10)
self.assertEqual(len(root), 2)
self.assertEqual(len(left), 1)
right = root.add_right(20)
self.assertEqual(len(root), 3)
self.assertEqual(len(left), 1)
self.assertEqual(len(right), 1)
ll = left.add_left(40)
self.assertEqual(len(root), 4)
self.assertEqual(len(left), 2)
self.assertEqual(len(right), 1)
self.assertEqual(len(ll), 1)
lr = left.add_right(50)
self.assertEqual(len(root), 5)
self.assertEqual(len(left), 3)
self.assertEqual(len(right), 1)
self.assertEqual(len(ll), 1)
self.assertEqual(len(lr), 1)
rl = right.add_left(60)
self.assertEqual(len(root), 6)
self.assertEqual(len(left), 3)
self.assertEqual(len(right), 2)
self.assertEqual(len(ll), 1)
self.assertEqual(len(lr), 1)
self.assertEqual(len(rl), 1)
rr = right.add_right(70)
self.assertEqual(len(root), 7)
self.assertEqual(len(left), 3)
self.assertEqual(len(right), 3)
self.assertEqual(len(ll), 1)
self.assertEqual(len(lr), 1)
self.assertEqual(len(rl), 1)
self.assertEqual(len(rr), 1)
