13 Red-black Trees
13 Red-black Trees
Red-black trees are one of many search-tree schemes that are "balanced" in order to guarantee that basic dynamic-set operations take O(lgn) time in the worst case.
Red-black trees 是许多搜索树框架中得一个。这些树为了保证基本的动态集合在最坏情况下操作时间在0(lgn ),采取了自平衡。
A red-black tree is a binary tree that satisfies the following red-black properties:
1. Every node is either red or black.
2. The root is black.
3. Every leaf (NIL) is black.
4. If a node is red, then both its children are black.
5. For each node, all simple paths from the node to descendant leaves contain the same number of black nodes.
1 所有的节点非红即黑
2 根是黑的
3 叶子(Nil)也是黑得
4 一个节点是红得,孩子必定是黑的。
5 对于每个节点,从这个节点到叶子的任意路径包含同样数量的黑的。
red-black tree 的属性从2-5感觉都是针对黑色的限制。
an example of a red-black tree.
As a matter of convenience in dealing with boundary conditions in red-black
tree code, we use a single sentinel to represent NIL
All pointers to NIL are replaced by pointers to the sentinel T.nil
所有指向空的都被替换成指向哨兵 T.nil 了
In the remainder of this chapter, we omit the leaves when we draw red-black trees, as shown
We call the number of black nodes on any simple path from, but not including, a node x down to a leaf the black-height of the node, denoted bh(x)
13.2 Rotations
We change the pointer structure through rotation, which is a local operation in a search tree that preserves the binary-search-tree property.
我们通过rotation来改变指针结构。它是保留搜索树属性的一个本地操作。
13.3 Insertion
We can insert a node into an n-node red-black tree in O(lgn) time.
To do so, we use a slightly modified version of the TREE-INSERT procedure (Section 12.3) to insert node ́ into the tree T as if it were an ordinary binary search tree, and then we color z red.
Case1:
Case 2 and case 3
13.4 Deletion
Like the other basic operations on an n-node red-black tree, deletion of a node takes time O(lgn ). Deleting a node from a red-black tree is a bit more complicated than inserting a node .
First ,we need to customize the TRANSPLANT subroutine that Tree-Delete calls so that it applies to a red-black tree :
Here is the red-black delete tree program :
Finally, if node y was black, we might have introduced one or more violations of the red-black properties, and so we call RB-DELETE-FIXUP in line 22 to restore the red-black properties. If y was red, the red-black properties still hold when y is removed or moved, for the following reasons:
如果节点y是黑色的,我们可能引入一个或多个违反红黑树性质。如果y是红色的,则红黑树的性质能得到保证。原因如下:
1. No black-heights in the tree have changed.
黑色深度没有变化
2. No red nodes have been made adjacent. Because y takes z's place in the tree, along with z's color, we cannot have two adjacent red nodes at y's new position in the tree. In addition, if y was not ́'s right child, then y's original right child x replaces y in the tree. If y is red, then x must be black, and so replacing y by x cannot cause two red nodes to become adjacent.
没有红色节点相邻。因为y取代了z得位置,并且取得了z得颜色,z原来是具有红黑树属性的,所以替换了以后仍然有。
另外,如果y不是z的右孩子,则y的原来位置被x取代了。如果y是红色的话,那么x肯定是黑色的,所以被x取代y 不可能导致两个红色节点相邻。
3. Since y could not have been the root if it was red, the root remains black.
如果y是红色的话,y肯定不是根,因此根仍然保持黑色。
If node y was black, three problems may arise, which the call of RB-DELETE- FIXUP will remedy.
First, if y had been the root and a red child of y becomes the new root, we have violated property 2.
首先如果y是根,并且y的一个红孩子成为了新根,那么违反 根是黑色的 属性。
Second, if both x and x.p are red, then we have violated property 4.
如果x和x.p 是红色的,那么我们可能违反 红色节点不能相邻这一条。
Third, moving y within the tree causes any simple path that previously contained y to have one fewer black node. Thus, property 5 is now violated by any ancestor of y in the tree.
第三,如果移动y,那么任意一条原先包含y的路线可能比其他的路线少一条黑色,因此,从任意一节点到叶子的黑色节点数是相同的。
We can correct the violation of property 5 by saying that node x, now occupying y's original position, has an "extra" black.
我们可以纠正 第五条属性 通过将现在占据y的原来位置的x的属性 有一个额外的黑色。
That is, if we add 1 to the count of black nodes on any simple path that contains x, then under this interpretation, property 5 holds.
也就是说,在我们计算从任意一条包括x节点的简单路径的时候,多增加1就能保持 属性5 。
When we remove or move the black node y, we "push" its blackness onto node x.
当我们移动黑色节点y时,我们将她的黑色推到节点x上。
The problem is that now node x is neither red nor black, thereby violating property 1.
现在问题是现在的节点x既不是黑色也不是红色,违反了属性1.
Instead,node x is either "doubly black" or "red-and-black," and it contributes either 2 or 1, respectively, to the count of black nodes on simple paths containing x.
节点x是双黑,或红黑,在计算包含x的简单路径上它将分别贡献一个或两个。
The color attribute of x will still be either RED (if x is red-and-black) or BLACK (if x is doubly black).
x的属相将仍然是红色(如果x是红黑)或黑色(如果x是双黑)。
In other words, the extra black on a node is reflected in x's pointing to the node rather than in the color attribute.
换句话说,一个节点的额外的黑色反应了x得位置而非颜色属性。
Case1: x'sibling w is red
通过转化,转换成Case2,3,4 的任意一种
Case2 :x's sibling w is black ,and both of w's children are black
即x的兄弟,还有兄弟的孩子都是黑色,则让x的兄弟便红,x转移到x得父节点
Case3:x的兄弟是黑色,兄弟的右孩子是红色。则通过转换,转换成Case4
Case4:x的兄弟是黑色,兄弟的左孩子是红色。这个就可以解决黑色节点的问题。
13 Red-black Trees的更多相关文章
- Red–black tree ---reference wiki
source address:http://en.wikipedia.org/wiki/Red%E2%80%93black_tree A red–black tree is a type of sel ...
- 【wiki】红帽linux
Red Hat Enterprise Linux From Wikipedia, the free encyclopedia wiki 上面红帽的版本信息. https://en.wikipedia. ...
- 深入探索RB-tree数据结构
引子 部门在各个团队推广软件通用技能矩阵工具,希望通过度量找到能力薄弱点,引导团队进行改进.从我们团队的数据上看,团队在数据结构和算法上的短板明显,需要加强,这也是写这篇文章的背后的初衷. 数据结构和 ...
- OCJP(1Z0-851) 模拟题分析(五)over
Exam : 1Z0-851 Java Standard Edition 6 Programmer Certified Professional Exam 以下分析全都是我自己分析或者参考网上的,定有 ...
- 2015GitWebRTC编译实录16
新问题,看应该是视频编解码那里出问题了.找找看.WebRtc VoiceEngine codecs:ISAC/16000/1 (103)ISAC/32000/1 (104)Unexpected cod ...
- 转:Hide data inside pointers(在指针中隐藏数据)
该文介绍了如何使用指针中一些未使用的位来隐藏一些数据. When we write C code, pointers are everywhere. We can make a little extr ...
- 红黑树(三)之 Linux内核中红黑树的经典实现
概要 前面分别介绍了红黑树的理论知识 以及 通过C语言实现了红黑树.本章继续会红黑树进行介绍,下面将Linux 内核中的红黑树单独移植出来进行测试验证.若读者对红黑树的理论知识不熟悉,建立先学习红黑树 ...
- 【转】const和static readonly
我们都知道,const和static readonly的确很像:通过类名而不是对象名进行访问,在程序中只读等等.在多数情况下可以混用.二者本质的区别在于,const的值是在编译期间确定的,因此只能在声 ...
- (C#) What is the difference between "const" and "static readonly" ?
const int a must be initialized initialization must be at compile time readonly int a can use defaul ...
- linux内核-红黑树
//rbtree.h /* Red Black Trees (C) 1999 Andrea Arcangeli <andrea@suse.de> This program ...
随机推荐
- web 开发之js---页面缓存, jsp 缓存, html 缓存, ajax缓存,解决方法
有关页面缓存问题.这个问题上网找了好多.但发觉各种解决方法,都彼此分离,没有一篇统一的解决方法,本人近日,也遇到了页面缓存的问题,根据网上各页面缓存的解答,做了一个总结. 1.服务器端缓存的问题, 防 ...
- 使用jdbc对mysql进行增删改查
建立数据库和数据表 CREATE DATABASE `mysqlTest` DEFAULT CHARACTER SET utf8; CREATE TABLE `test` ( `id` ) NOT N ...
- lineage 世系 血缘 容错机制 DAG
当某个RDD的部分数据丢失时候,Saprk会根据记录的世系关系找到该RDD的父RDD以及更上级的RDD.只需要将该RDD依赖的上级RDD重新计算就可以将该RDD进行恢复. Directed Acycl ...
- UVa 12403 - Save Setu
题目:有两种操作:1.当前数值添加.2.输出当前数值. 分析:简单题.模拟就可以. 说明:A+B. #include <iostream> #include <cstdlib> ...
- CMMI Institute Conference 2014中国大会
我在大会上做SPD(Strategic Policy Deployment战略部署策略)的演讲,和来自各个公司的高管进行了热烈的讨论.获得好评. 有兴趣的朋友能够点击下面链接:Stratehttp:/ ...
- beego5---gosqlite安装
WindowsWindows下的安装也非常简单,只要到 SQLite3 的下载页面,下载 Windows 下的预编译包 DLL 的压缩包(sqlite-dll-win32-x86-XXX.zip),然 ...
- vmware中鼠标在部分区域不能使用
https://blog.csdn.net/dreamengsoul/article/details/80439278 方法1:重装VMware tools; 方法2:使用增强型键盘鼠标: 方法3:检 ...
- problem in Sourcetree
1.The date is commit date not the date of author 2.The log line is ordered by time, actually it sho ...
- 我的第一篇博文,Python+scrapy框架安装。
自己用Python脚本写爬虫有一段时日了,也抓了不少网页,有的网页信息两多,一个脚本用exe跑了两个多月,数据还在进行中.但是总觉得这样抓效率有点低,问题也是多多的,很早就知道了这个框架好用,今天终于 ...
- 杂项:IntelliJ IDEA
ylbtech-杂项:IntelliJ IDEA 1.返回顶部 2.返回顶部 3.返回顶部 4.返回顶部 5.返回顶部 6.返回顶部 作者:ylbtech出处:http:/ ...