Problem
Invert a binary tree.
Example:
Input:
4
/ \
2 7
/ \ / \
1 3 6 9
Output:
4
/ \
7 2
/ \ / \
9 6 3 1
Solution
class Solution:
def invertTree(self):
if root:
tmp = root.left
root.left = self.invertTree(root.right)
root.right = self.invertTree(tmp)
return root