What's New - March, 2006
March 26, 2006: The 15 Puzzle was
popularized by puzzle maker Sam Loyd in 1870 when he published
an unsolvable version in a New York newspaper offering a
$1000 reward for a solution. Many hours were spent
in fruitless attempts. It turns out that only 1/2 of the
possible configurations are solvable even though a DFF
viewer recently tried to convince me otherwise. Here is version 3
of our Sliding 15 puzzle
which will let him "cheat" by exchanging adjacent
tiles. The resulting failure to solve and
a "Parity" function are not proof, but
pretty convincing evidence.
March 23, 2006: Here's and updated version of our Inverted/Mirrored Text program which lets users set the background color. This will be useful to those using the program as a teleprompter and wanting white text on a black background.
March 20, 2006: Danijel Tkalcec has started a website to promote Delphi programming at www.fundelphi.org and a discussion group at http://groups.google.com/group/fundelphi . I've had a number of requests in the past to start a discussion group for DFF programs, but have avoided it because I like writing code better than writing about code. You're invited to take a look and participate if so inclined. The website has a rapidly growing list of other Delphi related sites for you to explore. Good luck, Danijel!
March 19, 2006: I spent so much time working on the Probability Calculator this week, that the wife has been making sarcastic comments about "planning a trip to the garage". Well, the program is posted now, so tomorrow I may even go to town with her and treat her to lunch.
It has been fun and educational, and the result may even be quite good - only time will tell. If you are into math things, check it out and let me know. It is not a tutorial, but addresses a range of common probability type problems from easy to perhaps intermediate, and should be at least handy for checking results you may calculate with pencil and paper.
March 12, 2006: Back from a pleasant week "off-property". Colonial Williamsburg in the slow season has the advantage of as much one-on-one time with the craftsmen as you care to spend, plus lodging a good rates ($110/per night for a 2 bedroom suite including breakfast and Williamsburg admission passes!) Nathan's 2nd birthday was a success with only an occasional test of that new found sense of independence. You could see the defiance wheels turning when the "Stop that" command conflicted his planned actions. Fortunately, his Mom gets to handle those situations.
Catching up on the Mensa Puzzle calendar when we got back, I ran across a decryption problem that prompted today's Simple Decrypt program posting to the Beginners page of our Delphi Techniques section. It implements a shift cipher (also known as "Caesar's Cipher") in about 40 lines of Delphi code and which will encrypt or decrypt input text.
March 2, 2006: We're heading out in the morning to spend a week visiting Colonial Williamsburg and celebrating birthdays with family (my 67th and grandson Nathan's 2nd). Word is out that the "Terrible twos" have kicked in early, so we'll see how goes.
In any event, here is one more little
puzzle program from the Mensa
Mind Challenges book, (I just noticed that there are a few
of these for sale at Amazon in the $5 range - a good
deal). The puzzle is called
Tree. It sets the task of entering digits 1 through 9
into a network of 7 circles so that the value in any
circle is the sum of the connected circles below it.
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