# 101 Symmetric tree

Apr 13, 2022

Check the problem description here

Solution

*Recursive solution*

Recursively check if the mirror nodes are same.

`class Solution:`

def isSymmetric(self, root: Optional[TreeNode]) -> bool:

if root:

return self.helper(root.left,root.right)

else:

return False

def helper(self,n1,n2):

if n1==None or n2==None :

return n1==n2

if n1.val != n2.val:

return False

return (self.helper(n1.left,n2.right) and self.helper(n1.right,n2.left))

*Time :O(N)*

*Space :O(h) h = height of tree*