def test_pre_order():
tree = BST(3)
tree.add(1)
tree.add(4)
actual = tree.print_tree("pre_order")
expected = '3-1-4-'
assert actual == expected
def test_post_order():
tree = BST(7)
tree.add(4)
tree.add(3)
tree.add(2)
tree.add(5)
tree.add(9)
tree.add(10)
assert tree.print_tree('post_order') == '2-3-5-4-10-9-7-'
def test_breadth_first_bst():
tree = BST(7)
tree.add(4)
tree.add(3)
tree.add(2)
tree.add(5)
tree.add(9)
tree.add(10)
assert tree.print_tree('breadth_first') == '7-4-9-3-5-10-2-'
def test_in_order():
tree = BST(7)
tree.add(4)
tree.add(3)
tree.add(2)
tree.add(5)
tree.add(9)
tree.add(10)
assert tree.print_tree('in_order') == '2-3-4-5-7-9-10-'