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…

题目如下: Given the root node of a binary search tree (BST) and a value to be inserted into the tree, insert the value into the BST. Return the root node of the BST after the insertion. It is guaranteed that the new value does not exist in the original B…

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…

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…

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)…

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…

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…

class Solution { public: vector<int> modes; int maxCnt = 0; int curCnt = 0; int curNum = 0; vector<int> findMode(TreeNode* root) { if (!root) { return modes; } curNum = root->val; inOrder(root); return modes; } void inOrder(TreeNode* root)…

Given the root node of a binary search tree (BST) and a value to be inserted into the tree, insert the value into the BST. Return the root node of the BST after the insertion. It is guaranteed that the new value does not exist in the original BST. No…