二叉查找树(Binary Search Tree),也称二叉排序树(binary sorted tree),是指一棵空树或者具有下列性质的二叉树: 若任意节点的左子树不空,则左子树上所有结点的值均小于它的根结点的值 任意节点的右子树不空,则右子树上所有结点的值均大于它的根结点的值 任意节点的左.右子树也分别为二叉查找树 没有键值相等的节点(no duplicate nodes) 本文地址:http://www.cnblogs.com/archimedes/p/binary-search-tree…

二叉查找树基础 二叉查找树(BST)满足这样的性质,或是一颗空树:或左子树节点值小于根节点值.右子树节点值大于根节点值,左右子树也分别满足这个性质. 利用这个性质,可以迭代(iterative)或递归(recursive)地用O(lgN)的时间复杂度在二叉查找树中进行值查找. 相关LeetCode题: 700. Search in a Binary Search Tree  题解 701. Insert into a Binary Search Tree  题解 450. Delete Node…

链接:https://leetcode.com/tag/binary-search-tree/ [220]Contains Duplicate III (2019年4月20日) (好题) Given an array of integers, find out whether there are two distinct indices i and j in the array such that the absolute difference between nums[i] and nums[…

二叉搜索树,它是映射的另一种实现 映射抽象数据类型前面两种实现,它们分别是列表二分搜索和散列表. 操作 Map()新建一个空的映射. put(key, val)往映射中加入一个新的键-值对.如果键已经存在,就用新值替换旧值. get(key)返回key对应的值.如果key不存在,则返回None. del通过del map[key]这样的语句从映射中删除键-值对. len()返回映射中存储的键-值对的数目. in通过key in map这样的语句,在键存在时返回True,否则返回False. 二叉…

二叉查找树简介 二叉查找树(Binary Search Tree), 也成二叉搜索树.有序二叉树(ordered binary tree).排序二叉树(sorted binary tree), 是指一棵空树或者具有下列性质的的二叉树: 1. 若任意节点的左子树不空,在左子树上所有结点的值均小于或等于它的根结点的值: 2. 任意节点的右子树不空,则右子树上所有结点的值均大于它的根结点的值: 3. 任意节点的左子树.右子树也分别为二叉查找树. 4. 没有键值相等的结点(no duplicate no…

@ 目录 1.二叉搜索树 1.1. 基本概念 1.2.树的节点(BinaryNode) 1.3.构造器和成员变量 1.3.公共方法(public method) 1.4.比较函数 1.5.contains 函数 1.6.findMin 1.7.findMax 1.8.insert 1.9.remove 二.完整代码实现(Java) 1.二叉搜索树 1.1. 基本概念 二叉树的一个性质是一棵平均二叉树的深度要比节点个数N小得多.分析表明其平均深度为\(\mathcal{O}(\sqrt{N})\)…

本质上是递归遍历左右后在与根节点做判断,本质上是后序遍历 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 给你一个二叉树,判断他是否是个有效的二叉查找树(BST). 假定一个BST树按照下面的内容定义: 左子树的节点的值都小于父节点. 右子树的节点的值都大于父节点. 左子树和右子树都得是合法的而二叉查找树. ++++++++++++++++++++++++++++++++++++…

二叉搜索树(Binary Search Tree),又名二叉查找树.二叉排序树,是一种简单的二叉树.它的特点是每一个结点的左(右)子树各结点的元素一定小于(大于)该结点的元素.将该树用于查找时,由于二叉树的性质,查找操作的时间复杂度可以由线性降低到O(logN). 当然,这一复杂度只是描述了平均的情况,事实上,具体到每一棵二叉搜索树,查找操作的复杂度与树本身的结构有关.如果二叉树的结点全部偏向一个方向,那么与线性查找将毫无区别.这就牵扯到二叉树的平衡问题,暂时不做考虑. 下面给出二叉搜索树的实现…

题目: Given a binary tree, determine if it is a valid binary search tree (BST). 知识点:BST的特点: 1.一个节点的左子树的全部点都小于或等于这个点的值.右子树的全部节点的值大于该节点的值: 2.最左节点值最小,最右节点值最大. 3.中序遍历结果值是一个非降的数列 问题:假设用Integer.MAX_VALUE会过不了測试用例,但是依照TreeNode中的定义.val值也是int呀.没办法用了Long.假设谁知道,麻烦…

问题描述: 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 tha…

题目描述: 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 tha…

二叉树(Binary Tree)是最简单的树形数据结构,然而却十分精妙.其衍生出各种算法,以致于占据了数据结构的半壁江山.STL中大名顶顶的关联容器--集合(set).映射(map)便是使用二叉树实现.由于篇幅有限,此处仅作一般介绍(如果想要完全了解二叉树以及其衍生出的各种算法,恐怕要写8~10篇). 1)二叉树(Binary Tree) 顾名思义,就是一个节点分出两个节点,称其为左右子节点:每个子节点又可以分出两个子节点,这样递归分叉,其形状很像一颗倒着的树.二叉树限制了每个节点最多有两个子节…

题目链接:Recover Binary Search Tree | LeetCode OJ 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 constan…

题目链接:Validate Binary Search Tree | LeetCode OJ 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…

Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target. Note: Given target value is a floating point. You may assume k is always valid, that is: k ≤ total nodes. You are guaranteed to have onl…

Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target. Note: Given target value is a floating point. You are guaranteed to have only one unique value in the BST that is closest to the target.…

Given an array of numbers, verify whether it is the correct preorder traversal sequence of a binary search tree. You may assume each number in the sequence is unique. Follow up: Could you do it using only constant space complexity? 这道题让给了我们一个一维数组,让我们…

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…

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 这道题是要求把有序链表转为二叉搜索树,和之前那道Convert Sorted Array to Binary Search Tree 将有序数组转为二叉搜索树思路完全一样,只不过是操作的数据类型有所差别,一个是数组,一个是链表.数组方便就方便在可以通过index直接访问任意一个元…

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 这道题是要将有序数组转为二叉搜索树,所谓二叉搜索树,是一种始终满足左<根<右的特性,如果将二叉搜索树按中序遍历的话,得到的就是一个有序数组了.那么反过来,我们可以得知,根节点应该是有序数组的中间点,从中间点分开为左右两个有序数组,在分别找出其中间点作为原中间点的左右两个子节点,这不就是是二分查找法的核…

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 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…

Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. Calling next() will return the next smallest number in the BST. Note: next() and hasNext() should run in average O(1) time and uses…

Given a binary search tree (See Definition) and a node in it, find the in-order successor of that node in the BST. If the given node has no in-order successor in the tree, returnnull. 分析: 给一个二叉查找树,以及一个节点,求该节点的中序遍历后继,如果没有返回 null. 一棵BST定义为: 节点的左子树中的值要严…

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}"…

二叉搜索树(BST,Binary Search Tree),也称二叉排序树或二叉查找树. 二叉搜索树:一棵二叉树,可以为空:如果不为空,满足以下性质: 非空左子树的所有键值小于其根结点的键值: 非空右子树的所有键值大于其根结点的键值: 左右子树都是二叉搜索树: Wiki中的定义: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a nod…

Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 题意:给一个升序排好的数组,构造一棵二叉查找树或者叫二叉搜索树BST,要求这颗树是平衡的 BST:二叉查找树,左子树所有节点都小于根节点.右子树所有节点都大于根节点,递归定义 堆(大根堆和小根堆)对应的二叉树:根节点大…

题目: 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, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 分析:这道题与unique binary…

Binary Search Tree Iterator Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. Calling next() will return the next smallest number in the BST. Note: next() and hasNext() should run in…