Given a binary tree, find the largest subtree which is a Binary Search Tree (BST), where largest means subtree with largest number of nodes in it. Note:A subtree must include all of its descendants.Here's an example: 10 / \ 5 15 / \ \ 1 8 7 The Large…

Given a binary tree, find the largest subtree which is a Binary Search Tree (BST), where largest means subtree with largest number of nodes in it. Note:A subtree must include all of its descendants. Example: Input: [10,5,15,1,8,null,7] 10 / \ 15 / \…

原题链接在这里:https://leetcode.com/problems/largest-bst-subtree/ 题目: Given a binary tree, find the largest subtree which is a Binary Search Tree (BST), where largest means subtree with largest number of nodes in it. Note:A subtree must include all of its d…

LeetCode:将有序数组转换为二叉搜索树[108] 题目描述 将一个按照升序排列的有序数组,转换为一棵高度平衡二叉搜索树. 本题中,一个高度平衡二叉树是指一个二叉树每个节点 的左右两个子树的高度差的绝对值不超过 1. 示例: 给定有序数组: [-10,-3,0,5,9], 一个可能的答案是:[0,-3,9,-10,null,5],它可以表示下面这个高度平衡二叉搜索树: 0 / \ -3 9 / / -10 5 题目分析 BST树的建立是唯一的吗?即使给定有序数组,我认为BST也是是不唯一的.…

作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 DFS 日期 题目地址:https://leetcode-cn.com/problems/largest-bst-subtree/ 题目描述 Given a binary tree, find the largest subtree which is a Binary Search Tree (BST), where largest means sub…

［抄题］: Given a binary tree, find the largest subtree which is a Binary Search Tree (BST), where largest means subtree with largest number of nodes in it. Note:A subtree must include all of its descendants. Example: Input: [10,5,15,1,8,null,7] 10 / \ 1…

Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node contains only nodes with keys…

Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note:A solution using O(n) space is pretty straight forward. Could you devise a constant space solution? confused what "{1,#,2,3}"…

Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 这道题实际上是Catalan Number卡塔兰数的一个例子,如果对卡塔兰数不熟悉的童鞋可能真…

Medium! 题目描述: 给定一个二叉树,判断其是否是一个有效的二叉搜索树. 一个二叉搜索树具有如下特征: 节点的左子树只包含小于当前节点的数. 节点的右子树只包含大于当前节点的数. 所有左子树和右子树自身必须也是二叉搜索树. 示例 1: 输入: 2 / \ 1 3 输出: true 示例 2: 输入: 5 / \ 1 4   / \   3 6 输出: false 解释: 输入为: [5,1,4,null,null,3,6].   根节点的值为 5 ,但是其右子节点值为 4 . 解题思路:…