/** * Definition for a binary tree node. * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */class Solution {    private int res=0;    private int count=0;    public int kthSmallest(TreeNode root, int k) {        inorder(root,k);        return res;    }    public void inorder(TreeNode root, int k){        if(root==null)return;        inorder(root.left,k);        count++;        if(count==k){             res=root.val;            return;        }         inorder(root.right,k);    }}