From 76772.1372@compuserve.com Thu Sep 10 11:39:15 1998 Date: Sat, 6 Sep 1997 10:43:38 -0400 From: William McKee <76772.1372@compuserve.com> To: BlindCopyReceiver:;@compuserve.com; Subject: Bad link [The following text is in the "ISO-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] John, Thanks for the text to your course on Data Structures and Algorithms. As a one-time Computer Science major during my ambivalent days of college, I regret having thrown out my notes and texts in my Data Structures course. Now that I'm trying to implement all these data structures, I've been having a hard time finding good resources and notes. Unfortunately the page (listed below) that I really need to read at your site is returning a 404 Not Found error. I hope you are able to get this fixed soon. http://ciips.ee.uwa.edu.au/~morris/PLDS210/n_ary_trees.html Cheers, Bill ---------------------------------------------------------------------------- Composed 06-Sep-1997 @ 07:43:10 MDT 76772.1372@compuserve.com Lopez Island WA, USA http://www.telluridecolorado.net/~knowmad/ From siah@net1.nw.com.au Thu Sep 10 11:39:23 1998 Date: Sat, 11 Oct 1997 02:03:34 +0800 From: siah@net1.nw.com.au To: morris@swanee.ee.uwa.edu.au Subject: B+ tree algorithm Hi, I'm looking for the B+ tree algorithm, which has to be implemented within a program created with Turbo Pascal, and was hoping you could help shed some light on this. If possible, do you know where I could obtain the B+ tree algorithms online via the Internet ? Thank you for your time and attention. Regards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e-mailing addresses : 190 Watts Road, |\ __,,,---,,_ --------------------- Wilson, /,`.-''` -. ;-;;,_ siah@net1.nw.com.au W.A 6107 |, * ) )-,_. ,\ ( `'-' dennisiah@usa.net '---''(_/--' `-'\_) dennisiah@pobox.org.sg dennisiah@mailhost.net http://www.curtin.edu.au * esiahden@alpha1.curtin.edu.au . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ---------------------------------------------------------------------------- From kyndallt@mindspring.com Thu Sep 10 11:40:01 1998 Date: Mon, 27 Oct 1997 20:12:13 -0600 From: Kyndall Taylor To: "'morris@ee.uwa.edu.au'" Subject: Punch Cards / Radix Sort I was reading through some of your web pages and noticed a brief desc. of the radix sort. I was wondering if you could help me with a question. How would you sort punch cards with around 5 char. names, with say, 10 bins. I have learned how to read the cards, but can't figure how to sort them with less than 26 bins. I am having a hard time getting any info on punch cards. Any help would be apprec. Thanks Kyndall Taylor ---------------------------------------------------------------------------- From MART041654@aol.com Thu Sep 10 11:40:27 1998 Date: Sat, 8 Nov 1997 21:20:51 -0500 (EST) From: MART041654@aol.com To: morris@swanee.ee.uwa.edu.au Subject: Data structures and algorithms Dear Sir? As a computer science student at the University of Binghamton, Binghamton, New York, I am very impressed with your course outline and web page notes. They are excellent. One question. Where is UWA located? I have no idea. Sincerely, Martin Patchett ---------------------------------------------------------------------------- From ivonne@dsi.com.mx Thu Sep 10 11:40:45 1998 Date: Mon, 17 Nov 1997 16:46:35 -0600 From: Laura Garay Reply-To: <@dsi.com.mx:@swanee> To: morris@swanee.ee.uwa.edu.au Subject: [ISO-8859-1] Re: Re: About yours courses´notes [The following text is in the "ISO-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] Dear John Morris: Thank a lot for your information, I have been seeking here about data structure and i have find enough for this course. If you don4t mind, I will aprecciate reading your notes in internet, and took some notes for myself. Thank again. Laura garay ---------------------------------------------------------------------------- > From: John Morris > To: Laura Garay > Subject: Re: Re: About yours courses4notes > Date: Miircoles 22 de Octubre de 1997 5:57 AM > > > > On Thu, 16 Oct 1997, Laura Garay wrote: > > > Dear Mr. Morris: > > I4m talking about data structures & algorithms. I have read your > > information but I would like to have it in paper and use in my class. I > > have read your introduction in that pages, and it saids that we can obtain > > your notes, but You don4t give your adreess. > > Yours Sincerely, > > Laura I. Garay. > ---------------------------------------------------------------------------- > From ivonne@dsi.com.mx Thu Sep 10 11:41:49 1998 Date: Fri, 10 Oct 1997 12:13:37 -0600 From: Laura Garay Reply-To: <@dsi.com.mx:@swanee> To: morris@swanee.ee.uwa.edu.au Subject: [ISO-8859-1] About yours courses´notes [The following text is in the "ISO-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] Dear John Morris, I4m Laura Garay from Mexico City. I4m electronic engineer and I take a master degree in electrical enginneering and I4m interested in having your course4s note. I would like to known how much it cost? and how could I get them? Thank you for your time and information. I4m looking foward to hear about you soon. Yours Sincerely, Laura I. Garay. ---------------------------------------------------------------------------- From 76207.2444@compuserve.com Thu Sep 10 11:42:02 1998 Date: Mon, 22 Sep 1997 07:15:20 -0700 From: John Bailey <76207.2444@compuserve.com> To: morris@swanee.ee.uwa.edu.au Subject: Huffman Encoding John, Great web site showing Huffman and other stuff (sorting, etc). THANK YOU VERY MUCH for providing the best material I have found on these subjects. I have one question. When I use Huffman to compress data, I'll get binary maps to leaves. Those maps will be varying lengths, from 1 or 2 to perhaps 4 bits. When I store those bits in a byte, then file, they will run together. When I go to decode them, how do I tell when a map "ends" (a 2-bit word from a 3-bit word)?? Thanks for your help. John Bailey ---------------------------------------------------------------------------- From rich7@flash.net Thu Sep 10 11:42:14 1998 Date: Sat, 21 Feb 1998 14:19:28 -0800 From: Ryan To: morris@swanee.ee.uwa.edu.au Subject: Your notes on data structures I have been searching for good information on the web regarding data structures. I must say you have put together an excellent source for this topic! I only wish I could have you as an instructor but since I am in the US it would be a little difficult :) Thank you for providing such information on the web. It will help me out a great deal as I teach myself this subject. Ryan Richards USA ---------------------------------------------------------------------------- From elliott@airfoil.cims.nyu.edu Thu Sep 10 11:42:35 1998 Date: Tue, 21 Apr 1998 12:14:44 -0400 From: frank w elliott jr To: morris@odin.ee.uwa.edu.au Cc: elliott@cims.nyu.edu Subject: your red-black tree implementation Dear Professor Morris, My name is Frank Elliott. I'm a research assistant professor at the Courant Institute for Mathematical Sciences at New York University. During a web search for an ANSI-C library implementing red-black trees, I found your implementation of red-black trees. I would like your permission to use this implementation temporarily in a non-commercial research code that I'm writing to do Domain Decomposition for the Helmholtz Equation. I would, of course, gladly give you full credit. If you decide not to give permission, I will also give you credit because your implementation and your web-pages have been a great help to this mathematician who is fairly ignorant of data structures. Thank you for your consideration. Very Best Regards, Frank ---------------------------------------------------------------------------- From mteves@ignacio.cs.xu.edu.ph Thu Sep 10 11:43:01 1998 Date: Tue, 3 Mar 1998 12:50:35 +0800 (PST) From: Ma Cecilia C Teves To: morris@swanee.ee.uwa.edu.au Subject: help... Hello there!!! I was thinking if you can help me out with the some of the code using Floyd's algorithm? I needed a code in C...thanks... very truly yours, Tetel :) ---------------------------------------------------------------------------- From jak@rudolph.ssd.hcsc.com Thu Sep 10 11:43:17 1998 Date: Mon, 6 Apr 1998 13:08:17 -0400 (EDT) From: Joe Korty To: John Morris Cc: jkorty@gate.net Subject: Data Structures and Algorithms Dear Mr. Morris, Thanks for making the stunningly clear `Data Structures and Algorithms' available to all via the web. I searched amazon.com for any books by you, but couldn't find any. I hope that someday you will expand this series into a book. Your approach to teaching I think would be appreciated by a great many people. Joe (Ft Lauderdale, Florida, USA) ---------------------------------------------------------------------------- From ahaning@hotmail.com Thu Sep 10 11:43:37 1998 Date: Sat, 30 May 1998 14:51:16 PDT From: Andy Haninger To: morris@ee.uwa.edu.au Subject: Sorts of sorts. Hello. I found your webpage while looking for info on the Quicksort. I'm trying to numerically sort an infinite amount of numbers without using more than one list. I tried the bubble sort and got it to work but it is too slow. Do you know of any other type of sort that may be of use and could you please describe, in generic terms, how it works(ie. "put lowest number last", etc.). Thanks Andy Haninger ahaning@hotmail.com ---------------------------------------------------------------------------- From avin98@yahoo.com Thu Sep 10 11:43:42 1998 Date: Thu, 28 May 1998 23:14:21 -0700 (PDT) From: avinash narasimhan To: morris@ee.uwa.edu.au Subject: student DEAR JOHN, I AM A STUDENT IN MY FIRST YEAR ENGG. IN INDIA . I HAPPENED TO VISIT YOUR SITE ON DATA-STRUCTURES AND FOUND THE MATERIAL PROVIDED ABSOLUTELY TOP CLASS . I WHOLE HEARTEDLY EXTEND MY CONGRATULATIONS AND SUPPORT FOR THE SITE CONTENTS . I HOWEVER COULD NOT GET THE ENTIRE CONTENTS IN DETAIL . I WOULD BE VERY PLEASED IF YOU COULD SEND ME THE CONTENTS OF YOUR COURSE AS AN ATTACHMENT TROUGH A .ZIP FILE . ELSE YOU CAN ALSO SEND ME THE WEB-SITES WHERE I CAN OBTAIN INFO ON DATA-STRUCTURES .MY BEST WISHES FOR YOUR FUTURE. PLEASE E-MAIL ME AT avin98@yahoo.com . bye! FROM AVINASH . ---------------------------------------------------------------------------- From riddhi@giascla.vsnl.net.in Thu Sep 10 11:43:48 1998 Date: Thu, 4 Jun 1998 23:34:27 +0530 From: Riddhi barman To: morris@ee.uwa.edu.au Subject: Appreciation and a question John, Visited your site on algos. Impressive ! I was wondering if you could help me out with this prob - I read about the postman sort which is supposed to be world's fastest sort ? But why ? It does not seem to be fundamentally diff. from a Bucket Sort ! If you know please email me at the address below.Thanks riddhi@giascla.vsnl.net.in ---------------------------------------------------------------------------- From lyang@chem.wisc.edu Thu Sep 10 11:43:53 1998 Date: Wed, 13 May 1998 11:54:16 -0500 From: Yang Lei To: morris@ee.uwa.edu.au Subject: hello hi, do you know where i can code in java for hash tables using chaining thx pls email to binglu@hotmail.com ---------------------------------------------------------------------------- From sukhbir@giasbmc.vsnl.net.in Thu Sep 10 11:44:16 1998 Date: Tue, 10 Mar 1998 20:10:21 -0500 (GMT) From: "DHILLON.SUKHBIR.SINGH" To: morris@ee.uwa.edu.au Cc: amol23@hotmail.com Subject: You are doing an excellent job! Can you also give some information abo Can you give some information regarding notions of N, NP ans NP-complete problems and order notation? Hoping an early reply from you soon! ---------------------------------------------------------------------------- Hello Mr. Morris, My name is Sidnei and I am currently studying computer science in an University here at Manaus, Amazonas, Brazil. I am actually working on binary trees implementations. I was looking for scientific and/or commercial use of binary tree codes, but unfortunatelly without much success. I found your page in a search engine on the net and would like to ask if you know any site that has the above subject. I saw that in your page you added some explanations of what a tree is, but I am needing to find whole systems based on binary trees structures. Since now I'd like to thank you a lot for your help ! ---------------------------------------------------------------------------- From paolo@mbox.ulisse.it Thu Sep 10 11:44:43 1998 Date: Thu, 23 Jul 1998 11:19:55 +0200 From: Paolo Campanella To: morris@ee.uwa.edu.au [The following text is in the "iso-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] Hello, I'm an Italian Student in Computer Engineering (well, my english is not that good...) and I only would like to thank you for the beautiful course; it's useful !!! Thank again. Paolo Campanella paolo@mbox.ulisse.it http://www.geocities.com/SouthBeach/Marina/8135 ---------------------------------------------------------------------------- From RAMONMC@santandersupernet.com Thu Sep 10 11:44:49 1998 Date: Fri, 31 Jul 1998 17:18:36 +0000 From: "[ISO-8859-1] Ramón Martínez Cazón" To: morris@ee.uwa.edu.au Subject: B-trees [The following text is in the "ISO-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] Hello! I´m a student at the University of Cantabria (North of Spain), and i´m doing a project on information retrieval, and the different ways of dealing with information. I´ve come up with your web page, wich i found much of my interest, searching around on the internet. ;-) Right now, I've arrived at the stage where i need to *phisically* implement binary trees on secondary memory (disk). I'd would be greatful if you could lead me to books or addresses on the internet where the implementation of B-trees is dealt with in detail (specially with C++). Thanx in advance. Un saludo. Ramón. ---------------------------------------------------------------------------- From RAMONMC@santandersupernet.com Thu Sep 10 11:45:04 1998 Date: Tue, 4 Aug 1998 10:22:19 +0000 From: "[ISO-8859-1] Ramón Martínez Cazón" To: John Morris Subject: Re: B-trees [The following text is in the "ISO-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] Hello! > I doubt whether you'll be lucky enough to find something that will give > you exactly what you want without some work .. [...] > disc if it's large. > (Some Unix flavours may allow you to map memory to a file .. check the > documentation .. making it unnecessary to go through the loading > exercise.) > > Hope this is useful, > Thank you very much for your help. Ramon. ---------------------------------------------------------------------------- From MegaMan_X@digitalparadise.cgocable.ca Thu Sep 10 11:45:29 1998 Date: Sun, 09 Aug 1998 02:11:42 -0400 From: MegaMan_X To: morris@ee.uwa.edu.au Subject: Huffman introduction Hi, just wanted to tell you your Huffman introduction doc is really easy to understand (the best I found on the net so far). One thing, however, still seems vague : your demonstration on how to build the tree is easy to follow, but what I'm wondering is how to implement that in actual code (assembler). Is there any "shortcut" to make use of an array for the tree (and encoded tree, the one to be sent with the encoded data). Thanks ---------------------------------------------------------------------------- From ernanif@nutecnet.com.br Thu Sep 10 11:46:07 1998 Date: Mon, 16 Feb 1998 14:51:32 -0300 From: ernani leite ribeiro filho To: morris@swanee.ee.uwa.edu.au Subject: Data structures news groups Dear Mr Morris, I am a science computer student and I'm looking for data structures used in computer maps (GIS) software. How to represent the map chart if I decide build my own map CAD. I would like to know too news groups addresses about this subject. I'm sorry for my english. Thanks for read this. ---------------------------------------------------------------------------- From rganesan@cisco.com Thu Sep 10 11:46:39 1998 Date: Sat, 07 Mar 1998 19:04:47 +0000 From: Ganesan Ramu To: morris@ee.uwa.edu.au Cc: rganesan@cisco.com Subject: Data structures and Algorithms collection Hi Morris, Your Data Structures and Algorithms is really good. Programs were easy to understand. I found a bug in you insertion sort function given in the following url; http://www.ee.uwa.edu.au/~plsd210/ds/sorting.html#bubble The problem is with the first while loop. When the 2nd while loop exits before j becoming 0, the 1st while goes in infinite loop. Regards, Ganesan /* Insertion sort for integers */ void insertion( int a[], int n ) /* Pre-condition: a contains n items to be sorted */ { int i, j, v; /* Initially, the first item is considered 'sorted' */ /* i divides a into a sorted region, x= i */ for(i=1;i 0 ) { /* If this element is greater than v, move it up one */ while ( a[j-1] > v ) { a[j] = a[j-1]; j = j-1; } /* Stopped when a[j-1] <= v, so put v at position j */ a[j] = v; } } } ---------------------------------------------------------------------------- From pmcamero@socs.uts.EDU.AU Thu Sep 10 11:47:03 1998 Date: Thu, 18 Sep 1997 02:17:07 +1000 (EST) From: Paul Cameron To: morris@swanee.ee.uwa.edu.au Subject: Red-black trees - Notes on the web Dear Mr Morris Feel free to ignore this email, you're not obligated to reply :) I chanced upon this URL in the hope of learning about red-black trees, yet I'm extremely confused by some of the example code you include. http://ciips.ee.uwa.edu.au/~morris/PLDS210/red_black.html In this function, you have: rb_insert( Tree T, node x ) { /* Insert in the tree in the usual way */ tree_insert( T, x ); /* Now restore the red-black property */ x->colour = red; while ( (x != T->root) && (x->parent->colour == red) ) { if ( x->parent == x->parent->parent->left ) { /* If x's parent is a left, y is x's right 'uncle' */ ... OK, so if I insert "dog", then "cat" into the tree i'll have dog (red) / cat (red) Inserting "dog" is fine, because dog is at the root of the tree, so "while ( (x != T->root) && (x->parent->colour == red)" will prevent anything bad from happening. When inserting "cat" ... errr while ( (x != T->root) && (x->parent->colour == red) ) { if ( x->parent == x->parent->parent->left ) { /* If x's parent is a left, y is x's right 'uncle' */ If "dog" is "cat"s parent, then who is "dog"s parent ? If "dog" has no parent, and I don't see why it would have one being the root node, then is the code (logically) correct ? Regards, Paul