April 2005 - Posts

• Weird Math Stuff II

  I left off last time explaining how invertible function spaces naturally form a group and how that leads to the concept of a group action. This concept turns out to be useful in examining any group, not just explicit function spaces. Any group G can be Read More... Posted Wednesday, April 27, 2005 7:55 PM by ReuvenLax | 0 Comments Filed under: Mathematics

• Math Puzzler Solution

  There are many solutions to this problem. Here's an easy one that everybody can understand. Let's construct a bipartite graph representing this problem. On the left side, we have a vertex for every integer lattice point (i.e. (0,0) (0,1) (1,1) etc.). Read More... Posted Monday, April 25, 2005 4:51 PM by ReuvenLax | 0 Comments Filed under: Mathematics

• Code Puzzler

  What does the following code snippet do? bool test(const wstring& first, const wstring& second) { if (first.empty() && second.empty()) return true; if (first.empty()) return (second[0] == L'*') && test(first, second.substr(1)); Read More... Posted Thursday, April 21, 2005 8:07 PM by ReuvenLax | 5 Comments Filed under: Algorithms, Programming, Computer Science

• Math Puzzler

  Another quick problem before I head to sleep. Let T be a rectangle in the plane, and let the rectangle T1, T2, ..., Tn tile T. By this I mean that each of the tiling rectangles is contained in T, the union of all the rectangles equals T, and the intersection Read More... Posted Friday, April 22, 2005 3:29 AM by Reuven | 0 Comments Filed under: Mathematics

• Weird Math Stuff

  I'm going to diverge a bit from software topics today and talk about some wild and wonderful math topics. I haven't seriously thought about advanced math since I graduated, but recently some topics have started coming to mind. One of the strangest results Read More... Posted Thursday, April 21, 2005 5:27 PM by ReuvenLax | 1 Comments Filed under: Mathematics

• Handling Errors

  Proper handling of errors is one of the bugbears of software development. In Win32 most function can return an error code of some sort, and a good programmer will always check these errors or risk undefined behavior. Various attempts have been made to Read More... Posted Tuesday, April 19, 2005 9:09 PM by ReuvenLax | 0 Comments Filed under: Programming, Windows Server, Windows XP

• Some words on performance

  In my list of afterthoughts, the third item is performance. Why don't developers like thinking about performance from the start? It's clearly not for the same reasons as backup and security, since performance is about a product working well. Nobody will Read More... Posted Tuesday, April 12, 2005 2:39 PM by ReuvenLax | 0 Comments Filed under: Algorithms, Programming, Computer Science

• What nobody thinks about

  When people develop software, there are three things that aren't thought about until the final stages of development. Security Backup Performance As a corollary, some might add Manageability. Now all of these topics will probably have some token representation Read More... Posted Thursday, April 07, 2005 1:21 PM by ReuvenLax | 1 Comments Filed under: VSS, Programming

• More on splay trees

  While discussing the weaknesses of splay trees, I realized that they have lots of problems in muli-threaded environments. Maintaining large trees in multi-threaded environments is always a challenge due to lock contention. The naive way of implementing Read More... Posted Wednesday, April 06, 2005 9:44 PM by ReuvenLax | 2 Comments Filed under: Algorithms, Programming, Computer Science

• First Post: cool data structures

  A couple of weeks ago I started a personal blog on livejournal, http:\\www.livejournal.com\users\groovinsax, to chronical a trip to Argentina. That blog will remain my personal blog, while this blog will focus on my technical interests and my job at Microsoft. Read More... Posted Wednesday, April 06, 2005 9:37 PM by ReuvenLax | 4 Comments