April 30, 2002:   I mailed DFF Newsletter #26 yesterday with  graphics missing -actually  embedded as links to their Internet home.    Here's my defense:  I switched to MS Outlook mail program this month and misinterpreted one of the options.  "Send pictures from Internet" option means "Include the pictures with email" , not "Leave pictures on the Internet" as I assumed.   Also we have DSL broadband service up on our mountain now (!),  so the fact that it was downloading the pictures during my test wasn't obvious.   I apologize if  your  mail reader tries to access the Internet to get those graphics.     It's corrected for next time and probably not worth resending the current issue since graphics all appear below anyway.    

April 29, 2002:  Here's Nim 2, the multi--pile version of that take away game.   This was originally intended to be an more challenging implementation of the Minimax search technique described last week. But it turns out that there is an even cooler algorithm based on the binary representations of the number of sticks in each pile.  It's good enough to let the computer defeat mere mortals most of the time.   

April 26, 2002:  I've been doing some housekeeping -  among other things the indices in the Programs section of the site are now in alphabetical order.   I also updated Permutes 1,  a program introducing permutations, the ways that a set of objects or numbers can be arranged.     And the new entry is  Permutes 2 which adds the ability to permute  subsets of a set of numbers,  and combinations, the ways to select subsets if order doesn't matter.     Permutes 2 also includes and tests the Combo unit, a unit providing a convenient interface for permutation and combination generation.   

April 24, 2002:  Jerry Pournelle of Byte magazine fame,  features a  Book of the Month in each column;  maybe I'll start doing the same.    This month it would definitely be Martin Gardner's The Colossal Book of Mathematics,  W.W.Norton, &  Co., 2001.  It's a collection selected by Gardner of the his 50 best "Mathematical Recreations" columns originally printed in Scientific American magazine.   This is the 17th published anthology of those columns, but if you are going to own only one, this is probably it.   

Chapter 3, "Palindromes: Words and Numbers" led directly to today's program, the third in the T-Shirt series,  T-Shirts #3,   Back of the shirt reads: "The only known non-palindromic integer whose cube is a palindrome"    The number on the front is ???.    Palindromes, by the way,  are numbers  (or words or sentences) that read the same from either end.

April  21, 2002:  This week we're beginning the investigation of a fairly major topic in the world of Computational Game Theory:  minimax search of game trees.  Minimax is a technique for finding good moves for a large class of two player games.   Today's  implementation is NIM, a simple  game that meets the minimax criteria.   Players alternate removing 1, 2, or 3 sticks from a pile; the player taking the last one loses.   Two hundred or so lines of code are enough to get the Delphi programmer started.   Non-programmers are welcome to download and play the executable version, but more interesting games of this type will follow.    

April 14, 2002:  Here's the link to the interesting online article, "Learn to Program in 10 Years",    that I  mentioned a few weeks ago.   Just ran across the reference  so thought I had better post it before it disappeared again.   

April 10, 2002:

I posted  a demo today over in Delphi Techniques showing how to include  Animated Cursors in Program Resource files.    I haven't figured out how to use animated cursors on Web pages yet though -  probably a blessing in disguise.  

April 8, 2002:  Here's the last version of Hangman: Hangman 2 - The Tricky Hangman.  It adds a dictionary and computer play to the earlier version.  The program plays the role of Convict about the same way as humans - it just does it better.   As Hangman, the program selects a random word from the dictionary and scores Convict responses.  The "Tricky"  Hangman may bend the rules just a little (but only to ensure that justice is served).