Leetcode 226. Invert Binary Tree

https://leetcode.com/problems/invert-binary-tree/

Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t invert a binary tree on a whiteboard so fuck off.

Solution:

# T:O(n) S:O(h)
class Solution(object):
    def invertTree(self, root):
        """
        :type root: TreeNode
        :rtype: TreeNode
        """
        if not root: return None
        root.left, root.right = root.right, root.left
        self.invertTree(root.left)
        self.invertTree(root.right)
        return root

Run Time: 40 ms