http://www.geeksforgeeks.org/diameter-of-a-binary-tree/ #include <iostream> #include <vector> #include <algorithm> #include <queue> #include <stack> using namespace std; struct node { int data; struct node *left, *right; node…

本文章转自洛谷 原作者: _皎月半洒花 一.简介线段树 ps: _此处以询问区间和为例.实际上线段树可以处理很多符合结合律的操作.(比如说加法,a[1]+a[2]+a[3]+a[4]=(a[1]+a[2])+(a[3]+a[4])) 线段树之所以称为“树”,是因为其具有树的结构特性.线段树由于本身是专门用来处理区间问题的(包括RMQ.RSQ问题等. 图片来源于互联网. 对于每一个子节点而言,都表示整个序列中的一段子区间:对于每个叶子节点而言,都表示序列中的单个元素信息:子节点不断向自己的父亲节点…

Segment Tree First, try to build the segment tree. lintcode suggest code: Currently recursion recommended. (For coding exercise, u can just start with "Interval minimum number" below.) """ Definition of SegmentTreeNode: class Segm…

Same Tree Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical and the nodes have the same value. Maximum Depth of Binary Tree Given a binary tree, find i…

Binary Tree Level Order Traversal Total Accepted: 79463 Total Submissions: 259292 Difficulty: Easy Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,…

遍历二叉树   traversing binary tree 线索二叉树 threaded binary tree 线索链表 线索化 1. 二叉树3个基本单元组成:根节点.左子树.右子树 以L.D.R分别表示遍历左子树.访问根节点.遍历右子树 可能的情况6种 排列A3 2 LDR LRD DLR DRL RLD RDL 若限定先左后右 LDR LRD  中根序遍历  后根序遍历 DLR  先根序遍历 先/中/后 序遍历…

# 树结构 from pythonds.basic.stack import Stack #pip install pythonds from pythonds.trees.binaryTree import BinaryTree from collections import defaultdict import json #JSON-esque def tree(): return defaultdict(tree) def dicts(t): return {k: dicts(t[k])…

In a tree, nodes have a single parent node and may have many children nodes. They never have more than one parent nor point to any siblings. The most common tree structure you see is a web page. The underlying structure is often called the "DOM tree&…

字典树(查找树) 26个分支作用:检测字符串是否在这个字典里面插入.查找 字典树与哈希表的对比:时间复杂度:以字符来看:O(N).O(N) 以字符串来看:O(1).O(1)空间复杂度:字典树远远小于哈希表 前缀相关的题目字典树优于哈希表字典树可以查询abc是否有ab的前缀 字典树常考点:1.字典树实现2.利用字典树前缀特性解题3.矩阵类字符串一个一个字符深度遍历的问题(DFS+trie) dfs树和trie树同时遍历 word searchIIdfs+hash:时间复杂度大,后面遍历到有些字符就…

Week2 - 669. Trim a Binary Search Tree & 617. Merge Two Binary Trees 669.Trim a Binary Search Tree Given a binary search tree and the lowest and highest boundaries as L and R, trim the tree so that all its elements lies in [L, R] (R >= L). You migh…