July 23, 2014: Feedback from the May posting of our Logic Solver program and an unsolved Geocaching problem led to Logic Version 5.4 posted today. Bug fixes include:
July 13, 2014:
StarsOnAGrid implements solving and allowing users to create, modify and solve puzzles of the type defined as follows::
Given a square N x N grid divided into N sections, place a star in each section with no two stars in the same column or row, and no two stars diagonally adjacent to each other.
The program allows grid sizes from 2x2 through 10x10, although no solutions
exist for sizes less than 5x5.
June 21, 2014: Self Describing Sentences, Version 2.2, posted today, adds a few extra examples of self-describing sentences or "Autograms" as Wikipedia calls them. I also added some run statistics and the ability to interrupt long running cases. Got to run. We're off to Kitty hawk and the beach today to spend a few days with daughter and family.
June14, 2014: Here's a Fill the Blanks Puzzle worth a few idle minutes of your time. The program makes it easy to validate that your choices are valid words and to explore alternatives. Another extract from the 2014 Mensa Puzzle-A-Day Calendar.
Many of the 10 given three-letter partial words have
more than one choice of final letter to form a common four-letter English word. Use all
of the supplied letters exactly once to fill the blanks and complete all these
May 28, 2014:
"Alphabet Long Division" is the 40th sample problem added to the our
Brute Force solver download since the
original posting in 2001. It is the perhaps the first problem to
extensively test the shorthand feature that treats character strings in
equations as multi-digit integers so we can define this problem with equations
like BRINK / RIB = RUN, RIB * R= OAR, etc. Click the
here if you have the
April program update and just want this new problem to play with.
May 24, 2014:
Time Trials Version 2 was posted today after scanning to see what robot
related programs I have posted. This is not a very good example but,
as usual, playing with it brought a few changes to mind. The "bug" needs
to be maneuvered around a "track" and through some gates in your best time.
Version 2 allows bug size to be adjusted (smaller bug makes it easier and faster
to complete the circuit). I can just break 20 seconds now
May 15, 2014:
We've been busy this month with spring chores (driveway reconditioning, garden preparation, waking up motorized stuff that slept all winter, etc.).
Tromino Puzzle Solver V1.0 is a medium size solver implemented on rainy days and evenings this month:
One or more copies of the 6 given shapes have been used to tile the grid and then the
outlines were removed. Can you fill them in again?
May 2, 2014: Another "geocacher" sent me a problem that my Logic Solver program is not solving so far. Several other Geocaching heavy-weights have apparently solved it however. The problem (in German) can be found at http://coord.info/GC3NRMZ. The current Logic Solver update to Version 5.3 has minor updates but the primary reason for the update to get more eyes to look at the problem to see of there are facts and rules in the description which I haven't picked up on or which the program fails to derive. A translation of the problem is included in the download files.
April 28, 2014: It has been a productive month for getting spring duties accomplished but not so productive programming-wise. I spent more hours than care to admit on two programs. Oscilloscope Version 4.2.4 was posted today with some cleanup of the diagnostics when an input device fails to open for display. I'll post our Logic problem solver tomorrow along with a problem which the program cannot solve and a request for help.
April 12, 2014: Here's another problem solvable by by our Brute
Force program which applies exhaustive search matching possible values with
variables in a set of equations.
Brute Force Version 3.1 adds the absolute value function, "abs", to
equation formats to enable solving the "Billiard Balls" problem. The
problem is to arrange 10 billiard balls into a triangle meeting a set of rules
about the balls numbered 1 through 10. One of the constraints is that the
balls in a particular row all have numbers more than 1 away from their
neighbors. This constraint for balls with numbers "a" and "b"
can be expressed with the equation "abs(a-b)>1". Sample problem
BilliardBalls.prb is included with the download and is solved in about one
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July 7, 2014: Note: this "Collapsible" month by month list of postings since year 2000 is not collapsing for some reason, making this a very large home page. Until it gets fixed, you can reference the complete quarter by quarter list of postings on the Newsletter page.
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