几何搜索 平衡搜索树(BST)在几何方面的应用,处理的内容变成几何对象,像点,矩形. 1d range search 先来看一维的情况,一维的范围搜索是后面的基础,处理的对象是在一条线上的点.这是符号表的一个小拓展,多了范围查找(range search) 和范围计数(range count)即希望知道给定范围上有哪些点或是有多少点. 用无序链表来实现的话,插入直接放开头,但是范围查找和范围计数都需要正比于 N 的时间.用有序数组来实现的话,范围计数的时间复杂度是 logN 级别,范围查找是 R…

Week 2 OverviewHelp Center Week 2 On this page: Instructional Activities Time Goals and Objectives Key Phrases/Concepts Guiding Questions Readings and Resources Video Lectures Tips for Success Getting and Giving Help Instructional Activities Below is…

二叉树(Binary Tree)是最简单的树形数据结构,然而却十分精妙.其衍生出各种算法,以致于占据了数据结构的半壁江山.STL中大名顶顶的关联容器--集合(set).映射(map)便是使用二叉树实现.由于篇幅有限,此处仅作一般介绍(如果想要完全了解二叉树以及其衍生出的各种算法,恐怕要写8~10篇). 1)二叉树(Binary Tree) 顾名思义,就是一个节点分出两个节点,称其为左右子节点:每个子节点又可以分出两个子节点,这样递归分叉,其形状很像一颗倒着的树.二叉树限制了每个节点最多有两个子节…

题目链接:Recover Binary Search Tree | LeetCode OJ 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 constan…

题目链接:Validate Binary Search Tree | LeetCode OJ 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…

http://www.hightopo.com/demo/astar/astar.html 最近搞个游戏遇到最短路径的常规游戏问题,一时起兴基于HT for Web写了个A*算法的WebGL 3D呈现,算法基于开源 https://github.com/bgrins/javascript-astar 的javascript实现,其实作者也有个不错的2D例子实现 http://www.briangrinstead.com/files/astar/ ,只不过觉得所有A*算法的可视化实现都是平面的不够…

Sept. 22, 2015 学一道算法题, 经常回顾一下. 第二次重温, 决定增加一些图片, 帮助自己记忆. 在网上找他人的资料, 不如自己动手. 把从底向上树的算法搞通俗一些. 先做一个例子: 9/22/2015 Go over one example to build some muscle memory about this bottom up, O(1) solution to find the root node in subtree function. Sorted List: 1…

Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target. Note: Given target value is a floating point. You may assume k is always valid, that is: k ≤ total nodes. You are guaranteed to have onl…

Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target. Note: Given target value is a floating point. You are guaranteed to have only one unique value in the BST that is closest to the target.…

Given an array of numbers, verify whether it is the correct preorder traversal sequence of a binary search tree. You may assume each number in the sequence is unique. Follow up: Could you do it using only constant space complexity? 这道题让给了我们一个一维数组,让我们…