def test_recursive_tree_maximum(self):
tree, nodes, keys = get_random_binary_search_tree()
actual_maximum = recursive_tree_maximum(tree.root)
assert_that(actual_maximum, is_in(nodes))
assert_that(actual_maximum.key, is_(equal_to(max(keys))))
def test_balance_subtree(self):
tree, nodes, _ = get_random_binary_search_tree()
assign_size_attributes(tree.root)
node = random.choice(nodes)
actual_balanced_node = balance_subtree(tree, node)
assert_binary_search_tree(tree)
assert_subtree_weight_balanced(actual_balanced_node)
def test_balance_subtree(self):
tree, nodes, _ = get_random_binary_search_tree()
assign_size_attributes(tree.root)
node = random.choice(nodes)
actual_balanced_node = balance_subtree(tree, node)
assert_binary_search_tree(tree)
assert_subtree_weight_balanced(actual_balanced_node)
def test_stackless_inorder_tree_walk(self):
tree, _, keys = get_random_binary_search_tree()
captured_output = io.StringIO()
with redirect_stdout(captured_output):
stackless_inorder_tree_walk(tree)
actual_output = [int(x) for x in captured_output.getvalue().splitlines()]
expected_output = sorted(keys)
assert_that(actual_output, is_(equal_to(expected_output)))
def test_inorder_tree_walk_(self):
tree, nodes, keys = get_random_binary_search_tree(min_size=0)
captured_output = io.StringIO()
with redirect_stdout(captured_output):
inorder_tree_walk_(tree)
actual_output = [int(x) for x in captured_output.getvalue().splitlines()]
expected_output = sorted(keys)
assert_that(actual_output, is_(equal_to(expected_output)))
def test_iterative_tree_search(self):
tree, nodes, keys = get_random_binary_search_tree(min_size=10, max_size=20, max_value=20)
key_to_find = random.randint(0, 20)
actual_node = iterative_tree_search(tree.root, key_to_find)
if key_to_find in keys:
assert_that(actual_node, is_in(nodes))
assert_that(key_to_find, is_(equal_to(actual_node.key)))
else:
assert_that(actual_node, is_(none()))
def test_tree_predecessor(self):
tree, nodes, keys = get_random_binary_search_tree()
given_node = random.choice(nodes)
actual_predecessor = tree_predecessor(given_node)
if actual_predecessor is None:
assert_that(given_node.key, is_(equal_to(min(keys))))
else:
assert_that(actual_predecessor, is_in(nodes))
assert_that(actual_predecessor.key, is_(less_than_or_equal_to(given_node.key)))
for node in nodes:
assert_that(node.key, is_not(all_of(greater_than(actual_predecessor.key), less_than(given_node.key))))
def test_safe_tree_delete(self):
tree, nodes, keys = get_random_binary_search_tree()
random.shuffle(nodes)
for node in nodes:
keys.remove(node.key)
safe_tree_delete(tree, node)
assert_binary_search_tree(tree)
assert_parent_pointers_consistent(tree)
actual_keys = get_binary_tree_keys(tree)
assert_that(actual_keys, contains_inanyorder(*keys))
def test_safe_tree_delete(self):
tree, nodes, keys = get_random_binary_search_tree()
random.shuffle(nodes)
for node in nodes:
keys.remove(node.key)
safe_tree_delete(tree, node)
assert_binary_search_tree(tree)
assert_parent_pointers_consistent(tree)
actual_keys = get_binary_tree_keys(tree)
assert_that(actual_keys, contains_inanyorder(*keys))
def test_iterative_tree_search(self):
tree, nodes, keys = get_random_binary_search_tree(min_size=10,
max_size=20,
max_value=20)
key_to_find = random.randint(0, 20)
actual_node = iterative_tree_search(tree.root, key_to_find)
if key_to_find in keys:
assert_that(actual_node, is_in(nodes))
assert_that(key_to_find, is_(equal_to(actual_node.key)))
else:
assert_that(actual_node, is_(none()))
def test_tree_delete(self):
tree, _, keys = get_random_binary_search_tree()
nodes = get_binary_tree_nodes(tree)
while nodes:
node = random.choice(nodes)
keys.remove(node.key)
tree_delete(tree, node)
assert_binary_search_tree(tree)
assert_parent_pointers_consistent(tree)
actual_keys = get_binary_tree_keys(tree)
assert_that(actual_keys, contains_inanyorder(*keys))
nodes = get_binary_tree_nodes(tree)
def test_tree_predecessor(self):
tree, nodes, keys = get_random_binary_search_tree()
given_node = random.choice(nodes)
actual_predecessor = tree_predecessor(given_node)
if actual_predecessor is None:
assert_that(given_node.key, is_(equal_to(min(keys))))
else:
assert_that(actual_predecessor, is_in(nodes))
assert_that(actual_predecessor.key,
is_(less_than_or_equal_to(given_node.key)))
for node in nodes:
assert_that(
node.key,
is_not(
all_of(greater_than(actual_predecessor.key),
less_than(given_node.key))))