--- layout: page title: Is Tree Symmetric? --- {% highlight python %} class TreeNode: def __init__(self, val): self.val = val self.left = None self.right = None def isSymmetric(root): def isMirror(left, right): if not left and not right: return True if left and not right: return False if right and not left: return False if left and right and left.val == right.val: return isMirror(left.left, right.right) and isMirror(left.right, right.left) return False if not root: return True return isMirror(root.left, root.right) root = TreeNode(0) root.left = TreeNode(2) root.right = TreeNode(2) root.left.left = TreeNode(3) root.right.right = TreeNode(3) print(isSymmetric(root)) {% endhighlight %} ![image1](https://bubblesortblog.files.wordpress.com/2020/05/img_20200501_163326.jpg?w=768)