/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/classSolution{publicbooleanisSymmetric(TreeNoderoot){returnisMirrorTree(root,root);}publicbooleanisMirrorTree(TreeNodeleft,TreeNoderight){if(left==null)returnright==null;if(right==null)returnleft==null;if(left.val==right.val)returnisMirrorTree(left.left,right.right)&&isMirrorTree(left.right,right.left);returnfalse;}}