Given a tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only 1 right child. Example 1: Input: [5,3,6,2,4,null,8,1,null,null,null,7,9] 5 / \ 3 6 / \ \ 2 4 8  …

problem 897. Increasing Order Search Tree 参考 1. Leetcode_easy_897. Increasing Order Search Tree; 完…

题目来源: https://leetcode.com/problems/increasing-order-search-tree/ 自我感觉难度/真实难度:medium/easy 题意: 分析: 自己的代码: 优秀代码: # Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class…

题目要求 Given a tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only 1 right child. 题目分析及思路 题目给出一棵树,要求重新对树进行排序,使得树中最左边的结点是树的根,并且每一个结点没有左孩子,只有一个右孩子.可以先得到已知树的中序遍历…

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 重建二叉树 数组保存节点 中序遍历时修改指针 参考资料 日期 题目地址:https://leetcode.com/problems/increasing-order-search-tree/description/ 题目描述 Given a tree, rearrange the tree in in-order so that the leftmo…

Given a tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only 1 right child. Example 1: Input: [5,3,6,2,4,null,8,1,null,null,null,7,9] 5 / \ 3 6 / \ \ 2 4 8  …

题目如下: 解题思路:我的方法是先用递归的方法找出最左边的节点,接下来再对树做一次递归中序遍历,找到最左边节点后将其设为root,其余节点依次插入即可. 代码如下: # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution(object): n…

这是悦乐书的第346次更新,第370篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第211题(顺位题号是897).给定一棵树,按中序遍历顺序重新排列树,以便树中最左边的节点现在是树的根,并且每个节点都没有左子节点,只有一个右子节点.例如: 输入:[5,3,6,2,4,null,8,1,null,null,null,7,9] 5 / \ 3 6 / \ \ 2 4 8 / / \ 1 7 9 输出:[1,null,2,null,3,null,4,null,5,null…

897. 递增顺序查找树 897. Increasing Order Search Tree 题目描述 给定一个树,按中序遍历重新排列树,使树中最左边的结点现在是树的根,并且每个结点没有左子结点,只有一个右子结点. LeetCode897. Increasing Order Search Tree 示例: 输入: [5,3,6,2,4,null,8,1,null,null,null,7,9] ``` 5 / \ 3 6 / \ \ 2 4 8 / / \ 1 7 9 ``` 输出: [1,nul…

1.题目描述 2/问题分析 利用中序遍历,然后重新构造树. 3.代码 TreeNode* increasingBST(TreeNode* root) { if (root == NULL) return NULL; vector<int> v; inorder(root,v); TreeNode* dummy = ); TreeNode *p = dummy; for (vector<int>::iterator it = v.begin(); it != v.end(); it+…

Given a tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only 1 right child. Example 1: Input: [5,3,6,2,4,null,8,1,null,null,null,7,9] 5 / \ 3 6 / \ \ 2 4 8  …

Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root. Example:Given a binary t…

题目:https://leetcode.com/problems/increasing-order-search-tree/ 题意: 将一棵二叉搜索树,重排为一棵递增的二叉排序树. 解法1: rson->root->left的顺序依次遍历整棵树,途中使用头插法建立链表(递增的二叉搜索树). 这样做会带来额外的内存开销. class Solution { public: TreeNode* result=NULL; TreeNode* increasingBST(TreeNode* root)…

LeetCode:Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST 分析:找到数组的中间数据作为根节点,小于中间数据的数组来构造作为左子树,大于中间数据的数组来构造右子树,递归解法如下 /** * Definition for binary tree * struct…

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 and the lowest and highest boundaries as L and R, trim the tree so that all its elements lies in [L, R] (R >= L). You might need to change the root of the tree, so the result should return the new root of the trimmed binary…

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…

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 递归 日期 题目地址:https://leetcode.com/problems/trim-a-binary-search-tree/description/ 题目描述 Given a binary search tree and the lowest and highest boundaries as L and R, trim the tree…

Given a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus sum of all keys greater than the original key in BST. Example: Input: The root of a Binary Search Tree like thi…

Sept. 22, 2015 学一道算法题, 经常回顾一下. 第二次重温, 决定增加一些图片, 帮助自己记忆. 在网上找他人的资料, 不如自己动手. 把从底向上树的算法搞通俗一些. 先做一个例子: 9/22/2015 Go over one example to build some muscle memory about this bottom up, O(1) solution to find the root node in subtree function. Sorted List: 1…

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…

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…

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 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…

原题链接在这里:https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/ 题目: 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 u…

Convert Sorted List to Binary Search Tree Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. Show Tags SOLUTION 1: 这个方法比较暴力,每次遍历当前list,找到中间的节点,建立 root,分别使用递归建立左树以及右树,并将左右树挂在root之下.但这个算法会复杂度很高…

501. Find Mode in Binary Search Tree 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 wi…

Given a binary search tree and the lowest and highest boundaries as L and R, trim the tree so that all its elements lies in [L, R] (R >= L). You might need to change the root of the tree, so the result should return the new root of the trimmed binary…

题目链接 题目要求: 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 node…