May 19, 2018:
This program lets you remove matchsticks by clicking. The objective is to remove the smallest possible number of matchsticks that will eliminate all squares of all sizes in th grid.
It finally happened - someone found a better solution for the 4x4 grid than
my program thought possible.
How Many Squaes Version 2 posted today
has a revised "best" solution target formula: See the linked page
for more details with a reward offered for a solution that beats by revised
May 18, 2018: "Cut List" shows woodworkers how to cut a set of parts from a set of available stock. This program creates diagram showings the stock pieces and how the required parts may be efficiently cut from them. A 2 line update today changed part diagram outlines from green to black. The previous green outlines and the light green fill color both mapped to the same shade of gray when printing in black/white and, if the parts were adjacent, part boundaries could disappear! Cutlist Version 4.05.1 posted today fixes that.
Here's a "Telephone words" program that converts number strings into words based on standard keypad number-to-letter assignments as illustrated here (e.g. 364 ==> DOG).
Businesses like phone numbers that can be presented as words with the idea that they are easy to remember. I (and probably most callers) dislike them because it slows and complicates the dialing process. But they do make interesting puzzles!.
One problem with real phone number is that they include "0"s and "1"s which have no associated letters. I ignore "0"s and use '1"s as space characters, allowing multi-word encoding.
One other problem when using numbers to encode messages is that there may be multiple translations. For example,46631364 not only decodes to:"GOOD DOG" but also to "HOOF FOG" and 12 other variations. For what it's worth, this program finds them all.
March 26, 2018:
Here's the February 23 Mensa puzzle that resulted in No Close Neighbors Version 3.0 posted today. Two added features for this puzzle make it several times more difficult that the original. It's only slightly more difficult for the computer program to solve, but much harder for humans trying to solve it manually or for the programmer trying to tell the program how to do it (me!).
The original puzzle did not allow repeated letters and told you where the
unused cells laid. This puzzle changes that. If you're up for a
challenge, check it out.
March 15, 2018: A few years ago, someone came looking for Delphi code to allow highlighting specific words in a DBGrid (database grid) control. I don't use DBGrids, but StringGrid controls serve as a good substitute, or so I thought. One of the StringGrid features not available in DBGrid was originally used to expand column widths when highlighting text size. Code was changed to eliminate use of hat feature, but the unused code remained in place. A fellow programmer wrote last week informing me of the problem when converting to use a DBGrid. GridWordHighlight Version 1.1 posted today, removes the offending code and should work for either grid type.
February 11, 2018:
Of the 450+ programs on DFF, Wordstuff is one of the two that have earned places on my desktop. BruteForce, an integer algebra solver is the other. These are the "go to" programs when I need help with our Daily Mensa© Calendar puzzles.
Wordstuff is a "wrapper"
for six programs solving or helping word based puzzles. Over the
years, many bugs fixes have been applied but enhancements can introduce new
ones. Updates today fix annoyances in the Word Completion and Unscramble
sections. Use the link above for more details and to download the program
February 5, 2018:
Cats love to chase mice, pirates love to chase merchant ships, and dogs love to chase rabbits. I recently received an interesting book titled "Chases and Escapes", (Paul Nahin, Princeton University Press). The math gets a little heavy (i.e.
Differential Equations), but the initial approach, the "Pursuit Curve"
illustrated here, is straight forward and fun to simulate. The Dog chases the
Rabbit by always heading toward its current location. If the dog runs faster
than the rabbit (and the field is large enough), he will always achieve his
goal. This rabbit has a hole where he's safe if he can run at least as
fast as the dog. In this Pursuit A program you can control the speed and the
dog's location when he spots the rabbit and starts the chase. Lots of room
here for enhancing this program or adding other chase strategies.
January 18, 2018: 3D Lab is an interesting program which draws one of several sample 3D objects viewed from multiple angles and elevations under user control. Even though the code is 20 years old, it implements the math behind virtually all of today's CGI productions. Much of the code here is likely implemented in hardware today. Thanks to Earl Glynn for publishing the original program and for permission to re-post it here with a little animation of figure rotation.
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