0101.Symmetric-tree

0101. Symmetric Tree

Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).

Example 1:

Input: root = [1,2,2,3,4,4,3]
Output: true

### Example 2:

Input: root = [1,2,2,null,3,null,3] Output: false