def test_post_order_traversal():
tree = BinaryTree()
tree.root = Node(1)
tree.root.left = Node(2)
tree.root.right = Node(3)
tree.root.left.left = Node(4)
tree.root.left.right = Node(5)
actual = tree.post_order()
expected = [4, 5, 2, 3, 1]
assert actual == expected
def test_postorder_traversal():
tree = BinaryTree()
node1 = Node(1)
node2 = Node(3)
node3 = Node(5)
node1.left = node2
node1.right = node3
tree.root = node1
actual = tree.post_order()
expected = [3, 5, 1]
assert actual == expected
def test_post_order():
tree = BinaryTree()
tree.root = Node(50)
tree.root.left = Node(25)
tree.root.right = Node(75)
tree.root.left.left = Node(20)
tree.root.right.right = Node(80)
tree.root.left.right = Node(40)
"""
50
25 75
20 40 80
"""
actual = tree.post_order()
expected = [20, 40, 25, 80, 75, 50]
assert actual == expected
def test_post_order():
grok = BinaryTree()
groot = Node('Groot')
i = Node('I')
am = Node('Am')
starlord = Node('Future Antman')
rocket = Node('Trash Panda')
grok.root = i
grok.root.left = am
grok.root.right = starlord
grok.root.left.left = groot
grok.root.left.right = rocket
assert grok.post_order() == [
'Groot', 'Trash Panda', 'Am', 'Future Antman', 'I'
]