//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
//
//
//
// Constraints:
//
//
// The number of nodes in the tree is in the range [1, 1000].
// -100 <= Node.val <= 100
//
//
//
//Follow up: Could you solve it both recursively and iteratively?
//
// Related Topics Tree Depth-First Search Breadth-First Search Binary Tree 👍 10
//559 👎 248
//leetcode submit region begin(Prohibit modification and deletion)
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
private boolean isSymmetricFunc(TreeNode leftNode, TreeNode rightNode) {
if (leftNode == null && rightNode == null) {
return true;
}
if (leftNode == null || rightNode == null || leftNode.val != rightNode.val) {
return false;
}
return isSymmetricFunc(leftNode.left, rightNode.right) && isSymmetricFunc(leftNode.right, rightNode.left);
}
}
//leetcode submit region end(Prohibit modification and deletion)
