This notebook was prepared by Donne Martin. Source and license info is on GitHub.
Input: 5 / \ 2 7 / \ / \ 1 3 6 9 Output: 5 / \ 7 2 / \ / \ 9 6 3 1
Refer to the Solution Notebook. If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start.
%run ../bst/bst.py
class InverseBst(Bst):
def invert_tree(self):
# TODO: Implement me
pass
The following unit test is expected to fail until you solve the challenge.
# %load test_invert_tree.py
import unittest
class TestInvertTree(unittest.TestCase):
def test_invert_tree(self):
root = Node(5)
bst = InverseBst(root)
node2 = bst.insert(2)
node3 = bst.insert(3)
node1 = bst.insert(1)
node7 = bst.insert(7)
node6 = bst.insert(6)
node9 = bst.insert(9)
result = bst.invert_tree()
self.assertEqual(result, root)
self.assertEqual(result.left, node7)
self.assertEqual(result.right, node2)
self.assertEqual(result.left.left, node9)
self.assertEqual(result.left.right, node6)
self.assertEqual(result.right.left, node3)
self.assertEqual(result.right.right, node1)
print('Success: test_invert_tree')
def main():
test = TestInvertTree()
test.test_invert_tree()
if __name__ == '__main__':
main()
Review the Solution Notebook for a discussion on algorithms and code solutions.