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…
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 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 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. 原题链接:https://oj.leetcode.com/problems/convert-sorted-list-to-binary-search-tree/ 题目:给定一个有正序链表,将其转换成一个二叉搜索树. 思路:能够依照之前的数组的思路来做.即找到中间值.再左右递归建树…
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…
Description: Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 给一个升序有序的数组,构建一个平衡的二叉查找树. 要平衡就要找中间的数来做头结点,递归构造. /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode lef…
---恢复内容开始--- Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 题目要求:转成高度平衡的二叉搜索树. 高度平衡的二叉搜索树:i)左子树和右子树的高度之差的绝对值不超过1; ii)树中的每个左子树和右子树都是AVL树; iii)每个节点都有一个平衡因子(balance factor bf),任一节点的平衡因子是1,0,…
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…
原题地址:http://oj.leetcode.com/problems/convert-sorted-array-to-binary-search-tree/ 题意:将一个排序好的数组转换为一颗二叉查找树,这颗二叉查找树要求是平衡的. 解题思路:由于要求二叉查找树是平衡的.所以我们可以选在数组的中间那个数当树根root,然后这个数左边的数组为左子树,右边的数组为右子树,分别递归产生左右子树就可以了. 代码: # Definition for a binary tree node # class…
题目: Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 思路: 总是取中间点为root package bst; public class ConvertSortedArrayToBinarySearchTree { public TreeNode sortedArrayToBST(int[] nums) { return constructBST(…
题意: 将一个有序的数组建成一棵平衡的BST树. 思路: 因为数组已经有序,每次可以从中点开始建根,再递归下去分别处理左/右子树. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Soluti…
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…
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…
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…
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. 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…
[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…
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…
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->…
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…
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…
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…