4.3 Given a sorted (increasing order) array with unique integer elements, write an algorithm to create a binary search tree with minimal height. 这道题给了我们一个有序的数组,让我们来生成一个最小高度的二叉搜索树,为了达到最小高度,肯定是尽可能的填成一个满二叉树,左子树填满,右子树尽可能的填满.而且要注意是二叉搜索树,左<根<右的性质不能忘.既然给了我…
Given a binary search tree (BST) with duplicates, find all the mode(s) (the most frequently occurred element) in the given BST. Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than or equal to the nod…
题目:验证二叉搜索树 难度:Medium 题目内容: 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 co…
Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. 首先是O(N)空间的方法,用递归: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeN…
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 O…
描述 解析 二叉搜索树,其实就是节点n的左孩子所在的树,每个节点都小于节点n. 节点n的右孩子所在的树,每个节点都大于节点n. 定义子树的最大最小值 比如:左孩子要小于父节点:左孩子n的右孩子要大于n的父节点.以此类推. 中序遍历 中序遍历时,输出的值,和前一个值比较,如果大,就失败. 代码 /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNo…
[096-Unique Binary Search Trees(唯一二叉搜索树)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 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 \ / / /…
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.…
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 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 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 confused what "{1,#,2…
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 confused what "{1,#,2…
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 一开始是想用递归解决,但看了标签是dp问题,就想了一下, 数目为k的bst,其每个 0 ~ k…
Given an integer n, generate all structurally unique BST's (binary search trees) that store values 1 ... n. Example: Input: 3 Output: [ [1,null,3,2], [3,2,null,1], [3,1,null,null,2], [2,1,3], [1,null,2,null,3] ] Explanation: The above outpu…
177. Convert Sorted Array to Binary Search Tree With Minimal Height Given a sorted (increasing order) array, Convert it to create a binary tree with minimal height. Example Example 1: Input: {1,2} Output: A binary search tree with minimal height. Exp…
4.7 Design an algorithm and write code to find the first common ancestor of two nodes in a binary tree. Avoid storing additional nodes in a data structure. NOTE: This is not necessarily a binary search tree. LeetCode上的原题,请参见我之前的博客Lowest Common Ancest…
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. Top down 的解题方法: 1. 将LinkedList的值保存到一个数组中,转化成Convert Sorted Array to Binary Search Tree 来解决 时间复杂度为O(n), 空间复杂度为O(n) /** * Definition for singl…
A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties: 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 greate…
/// Binary Search Tree - Implemenation in C++ /// Simple program to create a BST of integers and search an element in it #include<iostream> #include "cstdio" #include "queue" using namespace std; ///Definition of Node for Binary…
A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties: 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 greate…
A binary search tree is provided for efficiently organizing values for a set of items, even when values are duplicated. In generating the binary search tree, the value of each item in a set of values is determined. If a particular value is unique and…
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…
