Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as the lowest node in T that has…

本文同步发布在CSDN:https://blog.csdn.net/weixin_44385565/article/details/90701125 1099 Build A Binary Search Tree (30 分)   A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties: The left subtree of a node cont…

Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has…

Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has…

给定一棵二叉搜索树, 找到该树中两个指定节点的最近公共祖先. 详见:https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/description/ Java实现: 方法一: /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right;…

这次是二叉搜索树的遍历 感觉只要和二叉搜索树的题目,都要用到一个重要性质: 中序遍历二叉搜索树的结果是一个递增序列: 而且要注意,在递归遍历树的时候,有些参数如果是要随递归不断更新(也就是如果递归返回上层,参数也需要最新的),就要用全局变量,而不是传参,其实这就是全局变量的定义. 不过如果是保存每层递归内的信息,就需要传参数. 本题显然是需要全局参数 /** * Definition for a binary tree node. * public class TreeNode { * int…

Given the root node of a binary search tree (BST) and a value to be inserted into the tree, insert the value into the BST. Return the root node of the BST after the insertion. It is guaranteed that the new value does not exist in the original BST. No…

Given the root node of a binary search tree (BST) and a value. You need to find the node in the BST that the node's value equals the given value. Return the subtree rooted with that node. If such node doesn't exist, you should return NULL. For exampl…

终于到二叉树了,每次面试时最担心面试官问题这块的算法问题,所以接下来就要好好攻克它~ 关于二叉树的定义网上一大堆,这篇做为二叉树的开端,先了解一下基本概念,直接从网上抄袭: 先了解下树的概念,balabala~~: 更通俗的定义: 而二叉树就是树结构的一个经典树,也是要讨论的主题,下面再来看下二叉树的定义: 而用二叉树主要是用来干嘛呢?上次不是学习过了一个利用递归实现折半查找的算法(http://www.cnblogs.com/webor2006/p/7182756.html)么?而当时实现的前…

给定一个有相同值的二叉搜索树(BST),找出 BST 中的所有众数(出现频率最高的元素). 假定 BST 有如下定义: 结点左子树中所含结点的值小于等于当前结点的值 结点右子树中所含结点的值大于等于当前结点的值 左子树和右子树都是二叉搜索树 例如: 给定 BST [1,null,2,2], 1 \ 2 / 2 返回[2]. 提示:如果众数超过1个,不需考虑输出顺序 class Solution { public: map<int, int> check; int MAX = 0; vector…