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
Complexity:
%run ../bst/bst.py
class InverseBst(Bst):
def invert_tree(self):
if self.root is None:
raise TypeError('root cannot be None')
return self._invert_tree(self.root)
def _invert_tree(self, root):
if root is None:
return
self._invert_tree(root.left)
self._invert_tree(root.right)
root.left, root.right = root.right, root.left
return root
%%writefile 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()
Overwriting test_invert_tree.py
%run -i test_invert_tree.py
Success: test_invert_tree