题目要求 We want to use quad trees to store an N x N boolean grid. Each cell in the grid can only be true or false. The root node represents the whole grid. For each node, it will be subdivided into four children nodes until the values in the region it r…

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/construct-quad-tree/description/ 题目描述 We want to use quad trees to store an N x N boolean grid. Each cell in the grid can only be true or…

We want to use quad trees to store an N x N boolean grid. Each cell in the grid can only be true or false. The root node represents the whole grid. For each node, it will be subdivided into four children nodes until the values in the region it repres…

problem 427. Construct Quad Tree 参考 1. Leetcode_427. Construct Quad Tree; 完…

We want to use quad trees to store an N x N boolean grid. Each cell in the grid can only be true or false. The root node represents the whole grid. For each node, it will be subdivided into four children nodes until the values in the region it repres…

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 [LeetCode] 题目地址:https://leetcode.com/problems/same-tree/ Total Accepted: 126017 Total Submissions: 291619 Difficulty: Easy 题目描述 Given two binary trees, write a function to c…

Recover Binary Search Tree Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note: A solution using O(n) space is pretty straight forward. Could you devise a constant space solution? c…

题目要求 Invert a binary tree. 题目分析及思路 给定一棵二叉树,要求每一层的结点逆序.可以使用递归的思想将左右子树互换. python代码 # Definition for a binary tree node. # class TreeNode: #     def __init__(self, x): #         self.val = x #         self.left = None #         self.right = None class S…

题目要求 A binary tree is univalued if every node in the tree has the same value. Return true if and only if the given tree is univalued. 题目分析及思路 题目要求当输入的二叉树的每个结点都有相同的值则返回true,否则返回false.可以使用队列保存每个节点,用val保存root节点的值.如果弹出的数字不等于val不等于root节点就立刻返回false.如果全部判断完…

Validate Binary Search Tree Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key.The right subtree of a node co…