2023.03.13 Today's Challenge

https://leetcode.com/problems/symmetric-tree/

Symmetric Tree - LeetCode

class Solution:
    def isMirror(self, left, right):
        if not left and not right:
            return True
        if not left or not right:
            return False
        return left.val == right.val and self.isMirror(left.left, right.right) and self.isMirror(left.right, right.left)
    def isSymmetric(self, root: Optional[TreeNode]) -> bool:
        if not root:
            return True
        return self.isMirror(root.left, root.right)