def simple_tree():
#build a binary tree of three nodes in two levels
st = BinaryTree()
curr_root = TreeNode(3)
root_left = TreeNode(1)
root_right = TreeNode(7)
curr_root.left_child = root_left
curr_root.right_child = root_right
st.root_node = curr_root
return st
def unbalanced_tree():
#build a binary tree of seven nodes in four levels
ut = BinaryTree()
curr_root = TreeNode(6)
root_left = TreeNode(4)
root_left_left = TreeNode(2)
root_right = TreeNode(16)
root_right_left = TreeNode(10)
root_right_right = TreeNode(26)
root_right_right_right = TreeNode(42)
ut.root_node = curr_root
curr_root.left_child = root_left
curr_root.left_child.left_child = root_left_left
curr_root.right_child = root_right
curr_root.right_child.left_child = root_right_left
curr_root.right_child.right_child = root_right_right
curr_root.right_child.right_child.right_child = root_right_right_right
return ut
def balanced_tree():
#build a binary tree of seven nodes in three levels
bt = BinaryTree()
curr_root = TreeNode(7)
root_left = TreeNode(3)
root_left_left = TreeNode(1)
root_left_right = TreeNode(5)
root_right = TreeNode(11)
root_right_left = TreeNode(9)
root_right_right = TreeNode(13)
bt.root_node = curr_root
curr_root.left_child = root_left
curr_root.left_child.left_child = root_left_left
curr_root.left_child.right_child = root_left_right
curr_root.right_child = root_right
curr_root.right_child.left_child = root_right_left
curr_root.right_child.right_child = root_right_right
return bt
def test_empty_tree_instantiates():
tree = BinaryTree()
expected = None
actual = tree.root_node
assert actual == expected
def test_non_empty_binary_tree_fails():
fbt = BinaryTree()
root = TreeNode(7)
fbt.root_node = root
assert fbt.root_node.value != None
def test_non_empty_binary_tree_passes():
pbt = BinaryTree()
root = TreeNode(3)
pbt.root_node = root
assert pbt.root_node.value == 3
def test_empty_binary_tree_fails():
febt = BinaryTree()
assert febt != 7
def test_empty_binary_tree_instantiates():
et = BinaryTree()
assert et.root_node == None