劍指 對稱的二叉樹

 

/*
public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;

    }

}
*/
public class Solution {
    
    boolean isSymmetrical(TreeNode root){
        if(root == null )
            return true;
    
   }
   private boolean isDuiChen(TreeNode lnode, TreeNode rnode){
     if(lnode == null) return rnode == null;
     if(rnode == null) return false;
     if(lnode.val != rnode.val)
         return false;
     return isDuiChen(lnode.left, rnode.right) && (rnode.left, lnode.right);
   
  }
}