108.Convert Sorted Array to Binary Search Tree(Array; Divide-and-Conquer, dfs)

108. Convert Sorted Array to Binary Search Tree 109. Convert Sorted List to Binary Search Tree -- 将有序数组或有序链表转成平衡二叉排序树

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…

leetcode 108. Convert Sorted Array to Binary Search Tree 、109. Convert Sorted List to Binary Search Tree

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…

[Leetcode][JAVA] Convert Sorted Array to Binary Search Tree && Convert Sorted List to Binary Search Tree

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…

34. Convert Sorted List to Binary Search Tree && Convert Sorted Array to Binary Search Tree

Convert Sorted List to Binary Search Tree OJ: https://oj.leetcode.com/problems/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. 思想: 以中间点为根节点,按先序顺序…

LeetCode:Convert Sorted Array to Binary Search Tree,Convert Sorted List to Binary Search Tree

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…

Convert Sorted List to Binary Search Tree&&Convert Sorted Array to Binary Search Tree——暴力解法

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…

Leetcode: Convert sorted list to binary search tree (No. 109)

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…

【LeetCode】109. Convert Sorted List to Binary Search Tree 解题报告（Python）

[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…

【leetcode】Convert Sorted List to Binary Search Tree

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 List to Binary Search Tree——将链表转换为平衡二叉搜索树 &&convert-sorted-array-to-binary-search-tree——将数列转换为bst

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. 为了满足平衡要求,容易想到提出中间节点作为树根,因为已排序,所以左右两侧天然满足BST的要求. 左右子串分别递归下去,上层根节点连接下层根节点即可完成. 递归找中点,然后断开前后两段链表,并继续找…

LeetCode: Convert Sorted List to Binary Search Tree 解题报告

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…

leetcode -day19 Convert Sorted List to Binary Search Tree

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:…

LeetCode解题报告——Convert Sorted List to Binary Search Tree & Populating Next Right Pointers in Each Node & Word Ladder

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…

【一天一道LeetCode】#109. Convert Sorted List to Binary Search Tree

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…

[LeetCode] 109. Convert Sorted List to Binary Search Tree 把有序链表转成二叉搜索树

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…

[LeetCode] Convert Sorted List to Binary Search Tree 将有序链表转为二叉搜索树

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…

leetcode -- 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. 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…

Leetcode#109 Convert Sorted List to Binary Search Tree

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->…

[Linked List]Convert Sorted List to Binary Search Tree

Total Accepted: 57775 Total Submissions: 198972 Difficulty: Medium Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. (M) Convert Sorted Array to Binary Search Tree /** * Definition for sing…

LeetCode109 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. (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. *…

leetcode 【 Convert Sorted List to Binary Search Tree 】python 实现

题目: Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 代码:oj测试通过 Runtime: 178 ms # Definition for a binary tree node # class TreeNode: # def __init__(self, x): # self.val = x # self.left = No…

[Swift]LeetCode109. 有序链表转换二叉搜索树 | Convert Sorted List to Binary Search Tree

[leetcode]Convert Sorted List to Binary Search Tree @ Python

原题地址:http://oj.leetcode.com/problems/convert-sorted-list-to-binary-search-tree/ 题意:将一条排序好的链表转换为二叉查找树,二叉查找树需要平衡. 解题思路:两个思路:一,可以使用快慢指针来找到中间的那个节点,然后将这个节点作为树根,并分别递归这个节点左右两边的链表产生左右子树,这样的好处是不需要使用额外的空间,坏处是代码不够整洁.二,将排序好的链表的每个节点的值存入一个数组中,这样就和http://www.cnblog…

108.Convert Sorted Array to Binary Search Tree(Array; Divide-and-Conquer, dfs)

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 思路:使用二分法,将list的中间节点作为根节点,然后分别处理list左半边及右半边,以此递归. struct TreeNode { int val; TreeNode *left; TreeNode *right; TreeNode(int x) : val(x), left(NULL), right…

Convert Sorted Array to Binary Search Tree & Convert Sorted List to Binary Search Tree

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. Subscribe to see which companies asked this question 要点就是找到中心点,然后分别递归构造左边的数和右边的数 TreeNode* sortedArrayToBST(vector<int>& nums, int beg, int end) {…

109. Convert Sorted List to Binary Search Tree (List; Divide-and-Conquer, dfs)

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */…

【二叉查找树】05根据升序的链表构造二叉查找树【Convert Sorted List to Binary Search Tree】

利用递归,构造二叉查找树, ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 给一个升序的单向链表,把他转换成一个二叉查找树 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Given a singly linked list where elements are…

[LeetCode] Convert Sorted List to Binary Search Tree DFS,深度搜索

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. Hide Tags Depth-first Search Linked List 这题是将链表变成二叉树,比较麻烦的遍历过程,因为链表的限制,所以深度搜索的顺序恰巧是链表的顺序,通过设置好递归函数的参数,可以在深度搜索时候便可以遍历了. TreeNode * he…

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: 根据一个有序链表,得到一个平衡二叉搜索树,主要是根据快慢指针得到链表的中点,然后将链表分成两半 /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next…

leetcode 109 Convert Sorted List to Binary Search Tree ----- java

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 和上一题类似,把数组换成链表,所以可以两种做法: 1.把链表换成数组,然后用上一题的方法,这样会比较慢. 2.每次找到中间的点,作为节点,然后递归,其实原理还是二分查找. /** * Definition for singly-linked list. * public…

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