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…
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. 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…
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…
背景 很多场景下都需要将元素存储到已排序的集合中.用数组来存储,搜索效率非常高: O(log n),但是插入效率比较低:O(n).用链表来存储,插入效率和搜索效率都比较低:O(n).如何能提供插入和搜索效率呢?这就是二叉搜索树的由来,本文先介绍非平衡二叉搜索树. 非平衡二叉搜索树 规则 所有节点的左节点小于节点,所有节点的右节点大于等于自身,即:node.value >  node.left.value && node.value <= node.right.value. 示例…
目录 简介 AVL的特性 AVL的构建 AVL的搜索 AVL的插入 AVL的删除 简介 平衡二叉搜索树是一种特殊的二叉搜索树.为什么会有平衡二叉搜索树呢? 考虑一下二叉搜索树的特殊情况,如果一个二叉搜索树所有的节点都是右节点,那么这个二叉搜索树将会退化成为链表.从而导致搜索的时间复杂度变为O(n),其中n是二叉搜索树的节点个数. 而平衡二叉搜索树正是为了解决这个问题而产生的,它通过限制树的高度,从而将时间复杂度降低为O(logn). AVL的特性 在讨论AVL的特性之前,我们先介绍一个概念叫做平…
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. 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…
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 由于对于这个二叉搜索树的要求是其必须是其必须是平衡的,所以应该使用递归.首先找到二叉树的中点.然后由这个中点作为根节点递归的在从左右子树上面取节点构成一颗二叉树.代码如下所示: /** * Definition for singly-linked list. * struct L…