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Delphi For Fun Newsletter #53 July 16, 2009
The quarterly newsletter is late this time, but I have a few good excuses. One is just old age  it simply takes longer to do everything these days J. Plus, we spent two weeks traveling and attending grandkids high school graduations and the family without a graduate this year visited our place for a week over the 4^{th} of July. The garden is in full bloom and needs daily tending. Finally, our newest family member is having a major impact on programming productivity!
In addition to the direct impact shown here, I probably spend an hour per day animating his “mice” (cat toys, paper balls, tissues, string, bits of plastic wrappers, and anything else that moves when he bats at it). I’m also spending time building a “Cat Castle”, a 4x4 post with spiral steps leading up to an elevated platform. The plans call for an elaborate castle on top, but I’ll defer that until I see that he will actually use it.
Here is a summary of, and links to, the programs posted since our March newsletter.
April 4, 2009: While the design of the bookmark might be perfect, there was room to improve the implementation. Perfect Bookmark V4 was posted today with a few image and font handling enhancements. April 6, 2009: Brute Force is one of my favorite programs on the site. It can solve a wide range of puzzles/problems which have a restricted range of integer solutions. Give the program the possible variable values and the equations describing the conditions to be met, and the program does an exhaustive search for sets of values satisfying the conditions. The download files include 24 sample problems. Brute Force Version 2.3 posted today allows problems with fewer variable values than variables to be solved. The newly included "Binary Conversion" sample problem finds numbers between 6 and 16 with the two middle digits in the binary representation having the same value. April 12, 2009:
Concentration is the card game requiring that pairs
of facedown cards be drawn and replaced until a match is made. In case that
game is too easy,
Concentration Version 2 adds the option of requiring sets of three matching
cards be found before they are removed. April 22, 2009: It has been a while since we have had a beginners program posted, so here is one that some might have fun with. Number Words converts any input integer between 0 and a million to words. So 456,789 as input for example, displays the result "Four hundred fiftysix thousand seven hundred eightynine". About 60 lines of user written code do the job. May 1, 2009:
A week of
algebra, geometry, and trigonometry refreshers was enough to convince me what I
was already quite sure of, but had never proven, that parallel rays striking a
parabolic surface are indeed all reflected to a common focal point. Here is a
Parabolic Reflections program which applies the math to see where it takes
us. The web page steps through the required math. May 2, 2009: I decided last night that Parabolic Reflections posted yesterday should be able to display more information about the intermediate steps in defining the reflected ray. Parabolic Reflections Version 3.1 posted today corrects that deficiency.
May 7, 2009:
The objective of
the
Forbidden Connections Puzzle is to enter the digits 1 through 6 in the
circles in this diagram in such a way that no number is connected to its
adjacent value. (For example, there can be no line connecting the "3" circle
with the "2" circle or the "4" circle, etc.) The program allows user play,
finds the two valid solutions, and gives user hints if needed.
May 12, 2009: A housekeeping update today replaces DFF Library zipped file DFFLibV12 with DFFLibV13. The library file contains a number of units which are used in multiple programs here on DFF. Any of modified units methods included here reflect minor bug fixes or have already been included in source code of programs which required the enhancements . Library units which are currently duplicated in program source code will be removed as those programs are updated, so no need for any immediate action by programmers. The library zipped file contains text file DFFVLib13.txt describing the changes in this version. One program, Big IntegersTest, has also been reposted with new buttons to test the five new methods in our large integer class, TInteger, which resides in unit UBigIntsV3. May 14, 2009: Oops  I changed everything in the DFF Library update except the actual file name in the download code. I was clued by the fact that the old version, DFFLibV12, was the downloaded 23 times yesterday. If you were one, please try it again. May 19, 2009:
Today's
puzzle assignment, should you choose to accept it, is to rearrange the numbers 1
through 16 in a 4x4 grid so that the sum of any two adjacent numbers,
horizontally or vertically, form a prime number. (Prime numbers are positive
integers divisible only by 1 and themselves.) No credit given for the sample
shown here. J
After you give up,
program
Prime Pair Sums will show you the other 2991 ways to do it.
May 27, 2009:
Summer is
rapidly approaching and programming time is getting reduced by gardening, lawn
mowing, grandchildren graduating (2 more from high school this year). I
decided to post a puzzle from my future projects file that I had written a year
or so ago but never got around to document. The problem is
to
find all 5 digit
numbers that contain the same 5 digits when they are multiplied by 3.
Then, coincidentally, yesterday's Mensa PuzzleADay calendar had another
puzzle related to the number 3:
Find all 3 digit
numbers, N, which together with 2*N and 3*N contain the digits 1 through 9
exactly once.
Today's
Treble Puzzles posting solves both of these. June 8, 2009: Here
is a solitaire version of the classical Battleships game where, in addition to
the ship quantities and types, you are supplied with the number of ship parts
hidden in each row or column and a few preplaced ship parts.
Battleship Puzzle allows user play for a couple of sample problems which
will save a bushel of eraser crumbs over pencil and paper solutions
J.
June 14, 2009; Here is a "Ones" puzzle solver that finds solutions for two odometer puzzles from recent Car Talk radio programs:
My version also answers "How many numbers contain exactly 1 occurrence of 1?" and other variations for other odometer lengths up to 8 digits. June 16, 2009: We are off for a week or so to help, or at least congratulate, a third grandchild in his transition from high school to college. I decided to get one more program posted before the hiatus. SortHTMLByDate is a utility which will sort a webpage with dated entries, such as this home page, into ascending date sequence. Seems like a good idea for arranging entries for archival reading once they are moved to the “What's New Archives” as indexed at the bottom of the DFF home page. (Only are few have been converted so far as test cases.)
Two views of success. My truth is somewhere in between:
"Talent is cheaper than table salt. What separates the talented individual from the successful one is a lot of hard work. "  Stephen King (Author)
"A man is a success if he gets up in the morning and goes to bed at night and in between does what he wants to do. "  Bob Dylan (Musician)
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