题目 Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 分析 给定有序链表,构造平衡的二叉查找树. 与上题本质相同,只不过采用了不同的数据结构,本题关键在于准确求取链表节点数,并计算根节点所在位置,正确划分左右子树的子链表. 注意:指针处理,避免出现空指针引用. AC代码 /** * Definition for singly-…
题目 Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 分析 给定一个有序序列,构造一颗平衡的二叉查找树. 思想:序列中值构造根节点,递归,前半序列构造左子树,有伴序列构造右子树. AC代码 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNod…
Given an array where elements are sorted in ascending order, convert it to a height balanced BST. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more th…
[LeetCode]109. Convert Sorted List to Binary Search Tree 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/description/ 题目描述: Given a s…
108. Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the tw…
一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. (二)解题 本题大意:给定一个单向链表,构造出平衡二叉搜索树 解题思路:参考[一天一道Leet…
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…
原题地址 跟Convert Sorted Array to Binary Search Tree(参见这篇文章)类似,只不过用list就不能随机访问了. 代码: TreeNode *buildBST(ListNode *head, int len) { ) return NULL; ListNode *p = head; ; < len) { p = p->next; leftLen++; } TreeNode *node = new TreeNode(p->val); node->…
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never diffe…
108. Convert Sorted Array to Binary Search Tree 这个题使用二分查找,主要要注意边界条件. 如果left > right,就返回NULL.每次更新的时候是mid-1,mid+1. 自己推一下基本就可以验证了. class Solution { public: TreeNode* sortedArrayToBST(vector<int>& nums) { ,nums.size() - ); } TreeNode* ToBST(vecto…
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…
108. Convert Sorted Array to Binary Search Tree 描述 Given an array where elements are sorted in ascending order, convert it to a height balanced BST. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the…
Given an array where elements are sorted in ascending order, convert it to a height balanced BST. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more th…
108. 将有序数组转换为二叉搜索树 108. Convert Sorted Array to Binary Search Tree 题目描述 将一个按照升序排列的有序数组,转换为一棵高度平衡二叉搜索树. 本题中,一个高度平衡二叉树是指一个二叉树每个节点的左右两个子树的高度差的绝对值不超过 1. 每日一算法2019/5/17Day 14LeetCode108. Convert Sorted Array to Binary Search Tree 示例: 给定有序数组: [-10,-3,0,5,9…
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…
Problem Link: http://oj.leetcode.com/problems/convert-sorted-array-to-binary-search-tree/ Same idea to Convert Sorted Array to Binary Search Tree, but we use a recursive function to construct the binary search tree. # Definition for a binary tree nod…
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…
108. Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *ri…
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…
Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 很简单的二分法,只要给出Array的开始和结束下标作为参数传入即可. public TreeNode sortedArrayToBST(int[] num) { return constructBST(num,0,nu…
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.     可以采用类似于Covert Sorted Array to Binary Search Tree的方法,但是寻找中点对于链表来说效率较低 可以采用更高效的递归方式,无需寻找中点 注意引用传…
Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST.   每次把中间元素当成根节点,递归即可   /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * Tre…
1.  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. 分析:将一个升序排列的链表转换为平衡二叉搜索树,採用递归的方式,先找到链表的中点,作为二叉树的根,然后递归求解左右子树. 例如以下: class Solution { public:…
108. Convert Sorted Array to Binary Search Tree 思路:利用一个有序数组构建一个平衡二叉排序树.直接递归构建,取中间的元素为根节点,然后分别构建左子树和右子树.…
Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST.SOLUTION 1:使用递归解决. base case: 当索引值超过时,返回null. 递归主体:构造根节点,调用递归构造左右子树.并将左右子树挂在根节点上. 返回值:返回构造的根节点. GITHUB: https:…
1. 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. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth…
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…
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. 本来想在递归中不用for循环把问题解决点,想了很久不知道该怎么做,看了网上的答案,发现大家就是用的循环····· 用循环的话,就非常简单了,但是我写代码的时候,子函数用引用传参数的时候报错,不知道…
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. (Medium) 分析:  链表不同于数组的是需要先遍历一遍求出长度,然后再找到中点,其余思路与Convert Sorted Array to Binary Search Tree一致. 代码: /** * Definition for singly-linked list. *…