【【leetcode】Convert Sorted Array to Binary Search Tree】的更多相关文章

【leetcode】Convert Sorted Array 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.   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…

【leetcode】Convert Sorted Array to Binary Search Tree (easy)

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 有序数组变二叉平衡搜索树,不难,递归就行.每次先序建立根节点(取最中间的数),然后用子区间划分左右子树. 一次就AC了 注意:new 结构体的时候对于 struct TreeNode { int val; TreeNode *left; TreeNode *right; TreeNode(int x)…

【题解】【BST】【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.思路:对于树来说,自顶向下的递归是很好控制的,自底向上的递归就很容易让脑神经打结了.本来想仿照排序二叉树的中序遍历,逆向地由数组构造树,后来发现这样做需要先确定树的结构,不然会一直递归下去,不知道左树何时停止.代码: TreeNode *addNode(vector<int> &num, int…

【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…

【Leetcode】【Medium】Convert Sorted Array to Binary Search Tree

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 解题思路: 用一个有序数组,创建一个平衡二叉查找树. 为确保平衡,需要满足两子树的高度差不大于1,可以通过设置左子树结点数等于或者比右子树结点数多1,来实现. 那么每次取数组的中间位置后一个值,作为根结点,数组左边元素的插入左子树,数组右边元素插入右子树,依次类推. 代码: /** * Definiti…

【树】Convert Sorted Array to Binary Search Tree

题目: Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 思路: 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. /** * Definition for a binary tree node. * function TreeNode(val) { * this.val = val; * this.l…

【leetcode】Convert Sorted List to Binary Search Tree （middle）

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 思路:题目看上去好像很难,但实际上很简单,递归做就行,每次找到左右子树对应的子链表就行.一次AC. class Solution { public: TreeNode *sortedListToBST(ListNode *head) { if(head == NULL) retu…

【LeetCode OJ】Convert Sorted Array to Binary Search Tree

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] 108. Convert Sorted Array to Binary Search Tree 把有序数组转成二叉搜索树

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][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…

37. leetcode 108. Convert Sorted Array to Binary Search Tree

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.…

[LeetCode] 108. Convert Sorted Array to Binary Search Tree ☆(升序数组转换成一个平衡二叉树)

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…

LeetCode 108. Convert Sorted Array to Binary Search Tree （将有序数组转换成BST）

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…

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 108. Convert Sorted Array to Binary Search Tree （有序数组转化为二叉搜索树）

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…

【leetcode刷题笔记】Convert Sorted Array to Binary Search Tree

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 题解:递归就可以了. Java代码如下: /** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val =…

Java for LeetCode 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. 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…

leetcode 108 Convert Sorted Array to Binary Search Tree ----- java

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 给一个排好序的数组,然后求搜索二叉树 其实就是二分法,不难. /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNo…

LeetCode 108: Convert Sorted Array to Binary Search Tree DFS求解

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…

LeetCode OJ——Convert Sorted Array to Binary Search Tree

http://oj.leetcode.com/problems/convert-sorted-array-to-binary-search-tree/ 将一个升序的数组转换成 height balanced BST高度平衡的二叉搜索树,根据二叉搜索树的特征,所有比根节点小的值,都在根节点的左边,所有比根节点大的值,都在根节点的右边.建立的过程就是一个个的插入.但要求是高度平衡的,即不能是各种偏的那样,否则的话,搜索的代价会增大,最佳的时候是O(height),height balanced的时候…

Leetcode 之Convert Sorted Array to Binary Search Tree（54）

思路很简单,用二分法,每次选中间的点作为根结点,用左.右结点递归. TreeNode* sortedArrayToBST(vector<int> &num) { return sortedArrayToBST(num.begin(), num.end()); } template<typename RandomAccessIterator> TreeNode* sortedArrayToBST(RandomAccessIterator first, RandomAccess…

Leetcode#108 Convert Sorted Array to Binary Search Tree

原题地址 对于已排序数组,二分法递归构造BST 代码: TreeNode *buildBST(vector<int> &num, int i, int j) { if (i > j) return NULL; ; TreeNode *node = new TreeNode(num[m]); node->left = buildBST(num, i, m - ); node->right = buildBST(num, m + , j); return node; }…

[leetcode]108. Convert Sorted Array to Binary Search Tree构建二叉搜索树

构建二叉搜索树 /* 利用二叉搜索树的特点:根节点是中间的数 每次找到中间数,左右子树递归子数组 */ public TreeNode sortedArrayToBST(int[] nums) { return builder(nums,0,nums.length-1); } public TreeNode builder(int[] nums,int left,int right) { if (left>right) return null; int mid = (left+right)/2;…

[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 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…

LeetCode 108. 将有序数组转换为二叉搜索树(Convert Sorted Array to Binary Search Tree) 14

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: Convert Sorted Array to Binary Search Tree 解题报告

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:…

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_108. Convert Sorted Array to Binary Search Tree

108. Convert Sorted Array to Binary Search Tree Easy 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 t…

Convert Sorted Array 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. 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…