[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…
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…
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->…
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…
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:…
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 解题思路: 同上题,JAVA实现如下: public TreeNode sortedListToBST(ListNode head) { ArrayList<Integer> list=new ArrayList<Integer>(); while(head!=nu…
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…
二叉树的各种遍历方式都是可以建立二叉树的,例如中序遍历,就是在第一步建立左子树,中间第二步建立新的节点,第三步构建右子树 此题利用二叉搜索树的中序遍历是递增序列的特点,而链表正好就是递增序列,从左子树开始递归利用链表的数据 控制平衡是用的递归层数,用left和right来控制 /* 各序遍历也可以建立树 利用二叉搜索树的特点,用中序遍历建立二叉树 */ //要递归listnode,所以要用全局变量 ListNode node; public TreeNode sortedListToBST(Li…
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 Java解法 Python解法 日期 题目地址:https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/#/description 题目描述 Given an array where elements are sorted in ascending order,…
原题地址: https://oj.leetcode.com/problems/convert-sorted-list-to-binary-search-tree/ 题目内容: Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 方法: 单纯.如何安排插入顺序,使得一棵二叉排序树接近平衡? 你从中间开始插嘛.这样左子树和右子树之差或…
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. 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…
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…
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…
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.…
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…
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…
Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 题目标签:Tree 这道题目给了我们一个有序数组,从小到大.让我们把这个数组转化为height balanced BST. 首先来看一下什么是binary search tree: 每一个点的left < 节点 < right, 换一句话说,每一个点的值要大于左边的,小于右边的. 那么什么是heigh…
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…
https://leetcode.com/submissions/detail/32662938/ 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 t…
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 日期 题目地址:https://leetcode.com/problems/find-mode-in-binary-search-tree/#/description 题目描述 Given a binary search tree (BST) with duplicates, find all the mode(s) (the most freque…
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 日期 题目地址:https://leetcode.com/problems/insert-into-a-binary-search-tree/description/ 题目描述 Given the root node of a binary search tree (BST) and a value to be inserted into the t…
Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 解题思路: 首先要理解,什么叫做height balanced BST Java for LeetCode 110 Balanced Binary Tree,然后就十分容易了,JAVA实现如下: public TreeNode sortedArrayToBST(int[] nums) { return…
Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 解题思路: 1. 找到数组的中间节点将其置为根节点 2. 左边的即为左子树 3. 右边的即为右子树 4. 递归求解 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * Tr…
Question: 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 n…
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 涉及到二叉树的问题用递归的方法很容易理解.这个问题要求把一个升序排序的链表转换为一颗height balanced BST.转换的方式就是把链表的中间值作为树的根节点,中间值的左半部分转换为二叉树的左子树,中间值的右半部分转换为二叉树的右子树. 递归解决问题的步骤如下: 1. 如…