def reconstruct(in_lst, pre_lst, prev_val):
if not pre_lst:
return
lft_inodr, right_inodr = [], []
lft_preord, right_preord = [], []
n = pre_lst[0]
node = Node(n)
for in_n, pre_n in zip(in_lst, pre_lst):
if in_n < n:
lft_inodr.append(in_n)
if in_n > n:
right_inodr.append(in_n)
if pre_n < n:
lft_preord.append(pre_n)
if pre_n > n:
right_preord.append(pre_n)
node.left = reconstruct(lft_inodr, lft_preord, n)
node.right = reconstruct(right_inodr, right_preord, n)
return node
def insert(self, value):
pointer = None
node = self.root
new_node = Node(value)
while node:
pointer = node
if value < node.value:
node = node.left
else:
node = node.right
if not pointer:
# the tree is empty
self.root = new_node
elif value < pointer.value:
pointer.left = new_node
else:
pointer.right = new_node
def create_test_root(self):
root = Node(1)
root.left, root.right = Node(2), Node(3)
root.left.left, root.left.right = Node(4), Node(5)
root.right.left, root.right.right = Node(6), Node(7)
return root
def create_unbalanced_root(self):
root = Node(6)
root.left, root.right = Node(4), Node(7)
root.left.left, root.left.right = Node(2), Node(5)
root.left.left.left, root.left.left.right = Node(1), Node(3)
return root
def test_find_lowest_common_ancestor(self):
node_a, node_b = Node(2), Node(5)
expected_lca = Node(4)
result_lca = self.tree.find_lowest_common_ancestor(node_a, node_b)
assert_that(result_lca).is_equal_to(expected_lca)