剑指offerr--二叉搜索树的第k个结点

题目描述

给定一颗二叉搜索树，请找出其中的第k大的结点。例如， 5 / \ 3 7 /\ /\ 24 6 8 中，按结点数值大小顺序第三个结点的值为4。

/*public class TreeNode {    int val = 0;    TreeNode left = null;    TreeNode right = null;    public TreeNode(int val) {        this.val = val;    }}*/import java.util.Stack;public class Solution {TreeNode KthNode(TreeNode pRoot, int k){if(pRoot==null) return null;int i = 0;Stack<TreeNode> stack = new Stack<TreeNode>();TreeNode p = pRoot;while(p!=null || stack.size()!=0){while(p!=null){stack.add(p);p = p.left;}if(stack.size()!=0){p = stack.pop();if(++i==k){return p;}p = p.right;}}return null;}}