class TestBinarySearchTree(unittest.TestCase):
def setUp(self):
self.bst = None
def _initialize(self):
self._cleanup()
self.bst = BinarySearchTree()
lst = [5, 8, 2, 1, 3, 9, 7, 4, 6, 0]
for i in lst:
self.bst.insert(i)
def _cleanup(self):
if self.bst:
del(self.bst)
self.bst = None
def test_insert(self):
self._initialize()
self.assertEqual(len(self.bst), 10)
def test_delete(self):
self._initialize()
self.bst.delete(5)
self.assertEqual(len(self.bst), 9)
def test_iteration(self):
self._initialize()
lst = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
for i in self.bst.root:
self.assertTrue(i == lst[i])
def tearDown(self):
self._cleanup()
def test_insert_and_delete_tree(self):
bst = BinarySearchTree(10)
bst.insert(20)
self.assertEqual(bst.size(), 2)
bst = bst.delete(20)
self.assertEqual(bst.size(), 1)
bst = bst.delete(10)
self.assertEqual(bst.size(), 0)
def test_delete(self):
# Create a complete binary search tree of 7 items in level-order
items = [4, 2, 6, 1, 3, 5, 7]
bst = BinarySearchTree()
for item in items:
bst.insert(item)
# Delete the specific nodes
bst.delete(7)
assert bst.contains(7) is False
bst.delete(2)
assert bst.contains(2) is False
assert bst.root.left.data == 1
assert bst.root.left.left.data is None
def test_delete_root_node(self):
bst = BinarySearchTree(10)
bst.insert(20)
bst.insert(30)
bst.insert(5)
bst.insert(9)
self.assertEqual(bst.size(), 5)
bst = bst.delete(10)
self.assertEqual(bst.size(), 4)
def test_delete_method(self):
bst = BinarySearchTree(Node(50))
bst.insert(bst, Node(40))
bst.insert(bst, Node(70))
bst.insert(bst, Node(60))
bst.insert(bst, Node(80))
bst.delete(bst, 50)
self.assertEqual(bst.val, 60)
bst.delete(bst, 40)
self.assertIsNone(bst.left)
bst.delete(bst, 80)
self.assertIsNone(bst.right.right)
def test_delete(self):
items = [4, 2, 6, 1, 3, 5, 7]
bst = BinarySearchTree(items)
bst.delete(1)
assert bst.size == 6
assert bst.root.left.left == None
bst.delete(2)
assert bst.size == 5
assert bst.root.left.data == 3
bst2 = BinarySearchTree(items)
bst2.delete(4)
assert bst2.size == 6
assert bst2.root.data == 3
assert bst2.root.left.right == None
def test_delete_tree_size_1(self):
bst = BinarySearchTree(10)
self.assertEqual(bst.size(), 1)
bst.delete(10)
self.assertEqual(bst.size(), 0)