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…

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…

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…

［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…

nlgn就不说了..说n的方法. 这个题做了好久. 一开始想到的是post-order traversal. 左右都是BST,然后自己也是BST,返还长度是左+右+自己(1). 左右其中一个不是,或者自己不是的话,返还-1. 第一次尝试忽略了跳级问题,判断自己能不能和左右子树组成BST的情况是,自己必须比左子树的最大值大,比右子树的最小值小..所以害的自己造个变量记录最大最小值. 提交的时候改了半天,主要问题在于更新最大最小但是会后,既要以子树更新,又要以自己的VAL更新,一开始忽略了其中一种.…

题目要求 You have a list of points in the plane. Return the area of the largest triangle that can be formed by any 3 of the points. 题目分析及思路 给定一个平面上的一组点,要求得到由这些点中任意三个所能组成最大面积的三角形.可以对这一组点进行三三组合,然后利用已知三点求三角形面积的公式得到每一组点所对应的三角形面积,最后取其中的最大值即为所求. python代码 class…

题目要求 Given an array A of positive lengths, return the largest perimeter of a triangle with non-zero area, formed from 3 of these lengths. If it is impossible to form any triangle of non-zero area, return 0. 题目分析及思路 给定一个正整数数组,要求返回由这些数所能组成的周长最长且面积非零的三角…

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 / \ 15 / \ \ 1 8 7 The Largest…

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 Lar…