Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself). So what is the most frequent…

［抄题］: Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself). So what is the most fre…

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/most-frequent-subtree-sum/description/ 题目描述 Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum…

Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself). So what is the most frequent…

详见:https://leetcode.com/problems/most-frequent-subtree-sum/description/ C++: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ c…

遍历二叉树,用map记录sum出现的次数,每一个新的节点都统计一次. 遍历完就统计map中出现最多的sum Map<Integer,Integer> map = new HashMap<>(); public int[] findFrequentTreeSum(TreeNode root) { helper(root); int max = 0; List<Integer> list = new ArrayList<>(); for (int key : m…

Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself). So what is the most frequent…

Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself). So what is the most frequent…

Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself). So what is the most frequent…

Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself). So what is the most frequent…

463. Island Perimeterhttps://leetcode.com/problems/island-perimeter/就是逐一遍历所有的cell,用分离的cell总的的边数减去重叠的边的数目即可.在查找重叠的边的数目的时候有一点小技巧,就是沿着其中两个方向就好,这种题目都有类似的规律,就是可以沿着上三角或者下三角形的方向来做.一刷一次ac,但是还没开始注意codestyle的问题,需要再刷一遍. class Solution { public: int islandPerime…

突然很想刷刷题,LeetCode是一个不错的选择,忽略了输入输出,更好的突出了算法,省去了不少时间. dalao们发现了任何错误,或是代码无法通过,或是有更好的解法,或是有任何疑问和建议的话,可以在对应的随笔下面评论区留言,我会及时处理,在此谢过了. 过程或许会很漫长,也很痛苦,慢慢来吧. 编号 题名 过题率 难度 1 Two Sum 0.376 Easy 2 Add Two Numbers 0.285 Medium 3 Longest Substring Without Repeating C…

All LeetCode Questions List(Part of Answers, still updating) 题目汇总及部分答案(持续更新中) Leetcode problems classified by company 题目按公司分类(Last updated: October 2, 2017) .   Top Interview Questions # Title Difficulty Acceptance 1 Two Sum Medium 17.70% 2 Add Two N…

All LeetCode Questions List 题目汇总 Sorted by frequency of problems that appear in real interviews. Last updated: October 2, 2017Google (214)534 Design TinyURL388 Longest Absolute File Path683 K Empty Slots340 Longest Substring with At Most K Distinct C…

源代码地址:https://github.com/hopebo/hopelee 语言:C++ 301. Remove Invalid Parentheses Remove the minimum number of invalid parentheses in order to make the input string valid. Return all possible results. Note: The input string may contain letters other tha…

终于将LeetCode的免费题刷完了,真是漫长的第一遍啊,估计很多题都忘的差不多了,这次开个题目汇总贴,并附上每道题目的解题连接,方便之后查阅吧~ 如果各位看官们,大神们发现了任何错误,或是代码无法通过OJ,或是有更好的解法,或是有任何疑问,意见和建议的话,请一定要在对应的帖子下面评论区留言告知博主啊(如果不方便注册博客园的话,可以下载下文提到的APP,在Feedback中给博主发邮件交流哈),同时也请大家踊跃地,大量地,盲目地提供各个题目的follow up一起讨论哈,多谢多谢,祝大家刷得愉快…

572. 另一个树的子树 572. Subtree of Another Tree 题目描述 给定两个非空二叉树 s 和 t,检验 s 中是否包含和 t 具有相同结构和节点值的子树.s 的一个子树包括 s 的一个节点和这个节点的所有子孙.s 也可以看做它自身的一棵子树. 每日一算法2019/6/12Day 40LeetCode572. Subtree of Another Tree 示例 1: 给定的树 s: 3 / \ 4 5 / \ 1 2 给定的树 t: 4 / \ 1 2 返回 true…

Given two non-empty binary trees s and t, check whether tree t has exactly the same structure and node values with a subtree of s. A subtree of s is a tree consists of a node in s and all of this node's descendants. The tree scould also be considered…

请点击页面左上角 -> Fork me on Github 或直接访问本项目Github地址:LeetCode Solution by Swift    说明:题目中含有$符号则为付费题目. 如:[Swift]LeetCode156.二叉树的上下颠倒 $ Binary Tree Upside Down 请下拉滚动条查看最新 Weekly Contest!!! Swift LeetCode 目录 | Catalog 序        号 题名Title 难度     Difficulty  两数之…

[1]Two Sum (2018年11月9日,k-sum专题,算法群衍生题) 给了一个数组 nums, 和一个 target 数字,要求返回一个下标的 pair, 使得这两个元素相加等于 target . 题解:我这次最大范围的优化代码, hash-table + one pass,时间复杂度 O(N),空间复杂度 O(N).重点在于动态找,一边生成hash-table的同时去找答案,不是先生成hash-table再开始找答案. //这种类似 hash 的能用 unordered_map 就不要…

[94]Binary Tree Inorder Traversal [95]Unique Binary Search Trees II (2018年11月14日,算法群) 给了一个 n,返回结点是 1 - n 的所有形态的BST. 题解:枚举每个根节点 r, 然后递归的生成左右子树的所有集合,然后做笛卡尔积. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * Tr…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 把自己刷过的所有题目做一个整理,并且用简洁的语言概括了一下思路,汇总成了一个表格. 题目的排列顺序是按照先Easy再Medium再Hard排列的,暂时还没有把题目全部整理完成.后序我会把刷过的所有的题目都整理到这个文档里. 题目 难度 解法 题目地址 566. Reshape the Matrix Easy 变长数组,求余法,维护行列计算在新的数组中的位置 https://blog.c…

1. sum-root-to-leaf-numbers Given a binary tree containing digits from0-9only, each root-to-leaf path could represent a number. An example is the root-to-leaf path1->2->3which represents the number123. Find the total sum of all root-to-leaf numbers.…

qwq以下都为9.24后写的模板 namespace IO{ const int S = 1 << 20; char I[S + 1], *Is = I, *It = I, O[S + 1], *Ot = O; char gc() {return Is == It ? ((It = (Is = I) + fread(I, 1, S, stdin)) == I ? EOF: *Is++): *Is++;} void flush() {fwrite(O, 1, Ot - O, stdout), O…

Path Sum II Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2], [5,8,4,5] ] 这个问题需要返…

树分治,设当前树的分治中心为x,其子树分治中心为y,则设father[y]=x,分治下去则可以得到一颗重心树,而且树的深度是logn. 询问操作(x,d),只需要查询重心树上x到重心树根节点上的节点的累加和.假设当前节点是y,那么节点y可以贡献的答案是那些以y为分治中心且到y距离为d-dis(x,y)的节点的总和.当然这样可能会出现重复的情况,重复情况只会出现在包含x的那颗子树上,因此减掉即可.修改操作类似.复杂度O(nlognlogn) 代码 #include<cstdio> #includ…

Problem Link: http://oj.leetcode.com/problems/binary-tree-maximum-path-sum/ For any path P in a binary tree, there must exists a node N in P such that N is the ancestor node of all other nodes in P. We call such N as the root of P, or P roots at N. T…

Frequent values 题意是不同颜色区间首尾相接,询问一个区间内同色区间的最长长度. 网上流行的做法,包括翻出来之前POJ的代码也是RMQ做法,对于序列上的每个数,记录该数向左和向右延续的最远位置,那么对于一个查询Q(L, R),它的答案就分成了三种情况right(L) - L,R - left(R)以及Q(L+right(L),R-left(R)). 这里给出一个线段树做法,在线段树的节点上维护3个量:l_value, r_value, value分别表示以左端点为起始点,以右端点为…

Problem 1 [Balanced Binary Tree] Given a binary tree, determine if it is height-balanced. 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 than 1. Pr…

Frequent values Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 13516   Accepted: 4971 Description You are given a sequence of n integers a1 , a2 , ... , an in non-decreasing order. In addition to that, you are given several queries cons…