LeetCode 226 – Python 3 (Week 3 – 06)

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def invertTree(self, root: TreeNode) -> TreeNode:
        
        #Recusive
        if not root: return None
        right = self.invertTree(root.left)
        left = self.invertTree(root.right)
        root.right = right
        root.left = left
        return root

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def invertTree(self, root: TreeNode) -> TreeNode:
        
        #Iterative
        if not root: return None
        current = root
        stack = []
        while stack or current:
            if current:
                stack.append(current)
                current = current.left
            else:
                current = stack.pop()
                current.right, current.left = current.left, current.right
                current = current.left
                
        return root