def setUp(self):
# The keys are unique house numbers in a street.
# The values are the names of inhabitants.
self.houses = [number for number in range(31, 36)]
self.people = ['Jane', 'John', 'Ann', 'Bob', 'John']
# Create trees for the tests to use.
# A brand new tree.
self.new = BinarySearchTree()
# An empty tree. Tests removal of single node.
self.empty = BinarySearchTree()
self.empty.add(self.houses[0], self.people[0])
self.empty.remove(self.houses[0])
# Tree with a single node, with highest key.
self.root = BinarySearchTree()
self.root.add(self.houses[-1], self.people[-1])
# Unbalanced tree: add the keys in ascending order.
self.linear = BinarySearchTree()
for house, person in zip(self.houses, self.people):
self.linear.add(house, person)
# Balanced tree: first add the median key.
self.balanced = BinarySearchTree()
self.balanced.add(33, 'Ann')
self.balanced.add(34, 'Bob')
self.balanced.add(35, 'John')
self.balanced.add(32, 'John')
self.balanced.add(31, 'Jane')
def test_can_create_complex_tree(self):
expected = TreeNode(
"4",
TreeNode("2", TreeNode("1", None, None), TreeNode("3", None,
None)),
TreeNode("6", TreeNode("5", None, None), TreeNode("7", None,
None)),
)
self.assertTreeEqual(
BinarySearchTree(["4", "2", "6", "1", "3", "5", "7"]).data(),
expected)
def test_can_sort_complex_tree(self):
expected = ["1", "2", "3", "5", "6", "7"]
assert BinarySearchTree(["2", "1", "3", "6", "7",
"5"]).sorted_data() == expected
def test_data_is_retained(self):
expected = TreeNode("4", None, None)
bst = BinarySearchTree(["4"])
self.assertTreeEqual(bst.data(), expected)
def test_can_sort_if_second_number_is_greater_than_first(self):
expected = ["2", "3"]
assert BinarySearchTree(["2", "3"]).sorted_data() == expected
def test_can_sort_if_second_number_is_same_as_first(self):
expected = ["2", "2"]
assert BinarySearchTree(["2", "2"]).sorted_data() == expected
def test_can_sort_single_number(self):
expected = ["2"]
assert BinarySearchTree(["2"]).sorted_data() == expected
def test_greater_number_at_right_node(self):
expected = TreeNode("4", None, TreeNode("5", None, None))
self.assertTreeEqual(BinarySearchTree(["4", "5"]).data(), expected)
def test_same_number_at_left_node(self):
expected = TreeNode("4", TreeNode("4", None, None), None)
self.assertTreeEqual(BinarySearchTree(["4", "4"]).data(), expected)
def test_smaller_number_at_left_node(self):
expected = TreeNode("4", TreeNode("3", None, None), None)
bst = BinarySearchTree(["4", "3"])
self.assertTreeEqual(bst.data(), expected)
