226.md

226. Invert Binary Tree

Example:

Input:

     4
   /   \
  2     7
 / \   / \
1   3 6   9
Output:

     4
   /   \
  7     2
 / \   / \
9   6 3   1

Space - O(h) ~ O(n) because its not a Balanced BT

Time - O(n)

class Solution(object):
    def invertTree(self, root):
        """
        :type root: TreeNode
        :rtype: TreeNode
        """
        if not root:
            return root
        
        temp = Solution.invertTree(self,root.left)
        root.left = Solution.invertTree(self,root.right)
        root.right = temp
        
        return root