July 2, 2013
Delphi For Fun Newsletter #68
We just returned from our third vacation with 16 members of our extended family (Grandma and me, our 3 children and their spouses, 7 of the 8 grandchildren and one "almost" granddaughter-in-law). A great time was had by all during the first week on a Mediterranean cruise and a second week in the beautiful Lauterbrunnen Valley in Switzerland where we took over an entire chalet at Valley Hostel. We missed out on the Strawberries and Mountain Laurel blossoms here at home but it was worth it. Also, the blueberries are coming on this week as compensation.
suffers during the summer but the quarter just ended has a few goodies which
might pique your interest. Here's the full list:
April 2, 2013: The Index of Lazarus conversions is now available as a link from the Lazarus Revisited page. Also, I just added the file of adage candidates which was missing from the Adage Anagrams program download posted in January.
April 6, 2013: One more fairly large conversion of Delphi to Lazarus posted today; the 6 individual word based programs (Crossword Helper, Decrypt, Scrambled Pie, Spellbound, Unscramble, and Word Ladder) plus the wrapper, Wordstuff 3, that links to any of them all wrapped up in a single zip file. I have added some notes to the Lazarus Revisited page. I've decided to post Lazarus notes there with the latest additions in red.
April 14, 2013:
Brain Game calendar puzzle solver was posted today. If you are a puzzleist
and need help finding the solution to this or a similar puzzle, download the
executable version of Expressions
From Integers. If you are a programmer or interested in how a computer
program might solve this puzzle and others like it, you might enjoy browsing the
text on the web page and/or the downloaded source code.
April 20, 2013: A viewer wrote last week regarding my "Know - Don't Know" program which analyzes a logic puzzle involving two people (usually professors), one given the sum of two numbers and the other given their product. By exchanging non-numeric messages about what they know or do not know, they both manage to find the numbers. It is often called the "Impossible Problem" because it seems that that should be the case. My original versions concentrated on finding the numbers without knowing either the sum or the product, but glossed over how the professors, particularly the one knowing only the sum, might have solved the problem. Know, Don't Know Version 3 posted today adds a "Walkthrough" page to the the program describing the thought processes of each professor at each exchange leading to them both finding the solution. It helped give me, and hopefully Charles and others, a deeper understanding of the problem and its solution.
April 23, 2013: An update to make Know, Don't Know Version 3.1 today added a second "Walk-through" page, this one interactive, taking any sum and product and stepping through the analysis from each professor's point of view. This was motivated by a viewer who doubted that the validity of the second solution for the 500 upper limit case. To eliminate the possibility that of a bug in the original solver code, I needed to step through as the Professors would have done. The size of the numbers makes this an order of magnitude harder than the first "Walk-through" and justified writing the additional code.
May 7, 2013: Here is a program which solves a problem discussed by computer science pioneer Donald Knuth in 1977 in a magazine article "Are Toy Problems Useful?" in 1977. He was disputing the argument made by another mathematician that the answer was "No". I agree with Knuth, that, like story problems in math textbooks, any problem which improves problem solving skills is useful even if the answer will not directly advance one's professional career. This problem presented by Knuth met the "useful" criteria for me. "Given an exponent, N, find all numbers which are equal to the sum of the Nth powers of their digits." For example for N =4: 1634 = 14 + 64 + 34 + 44 (= 1 + 1296 + 81 + 256 = 1634). Knuth Toy Problem has the results of my investigation, three methods which, for N=10, find the unique solution in 30 minutes, or 2 hours, or 2 seconds. A rare personal Eureka moment! The explanation for the best result is behind a button in case any programmer wants to discover it on their own J.
May 11, 2013: The original version of our "Copy Folder" utility program performed operations like copying all files in folder "ProgramA" to a new folder "ProgrtamA_Test". A viewer pointed out it did not work well for his intended use: i.e. copy folders "ProgramA", then "ProgramB", and then "ProgramC" into a folder named "Backups". In other words, copy the selected folder name as well as the files in that folder. It seemed like a reasonable request to me, so CopyFolder Version 3.2 posted today adds a checkbox: "Include selected input folder record in output" to do just that.
May 25, 2013: It has been a busy month with 2 grandchildren graduating from college, spring clean up of extensive winter damage and the always stressful planning for a big family vacation in June.
I did find time to update the 15 Graphic Effects program to Version 2 in our Delphi Techniques section. The update improves the efficiency of the "Magnifier" effect and has better scaling for demo images loaded. The original program was written 10 years ago by bright 16 year old Ivan Sivak. I emailed him the other day asking for a status update but haven't heard back yet.
Table at left shows an original photo and 4 of
the 15 special effects: Brightness/Contrast, Gray Scale, Blend, and
June 6, 2013:
Domino Search was posted several years ago to help solve a puzzle type I found in the book Logical Puzzles, Chartwell Books. (BTW, Amazon currently has used copies of the book starting at $4.00 shipped at this link.) In this program, the viewer is given an array of numbers representing dots on the 28 standard dominos, but without the domino outlines. The player's job is to replace them. The program was only partially successful because it could generate and solve random arrays it generated, it also allowed users to enter data and supported user play, but it didn't know how to solve those puzzles. The first step toward fixing this is a separate program which accepts and solves user submitted arrays and saves the array and solution in a file for input to Domino Search. Domino Search Version 5, and Define Domino Arrays Version 2 posted today are implementations of this strategy. Perhaps one day I'll get around to rolling them back into one program, but not today.
June 25, 2013: Back home from a wonderful family vacation; one week on a Mediterranean cruise, and a week in Switzerland. Ports visited were new for most of the family and it's been 8 years since the grandchildren were in Switzerland. Not much new for us, but we sure enjoyed watching all 8 of them renew friendships. Much laughter, a few adventures, and no serious misadventures made it a memorable 2 weeks!
Of the dozen or so DFF feedback emails awaiting me here at home, only one so far required a bug fix; the rest were comments or questions acknowledged or answered privately. Version 5.2 of our Logic Problem Solver program, posted today, allows new problems to be defined even after working on other problems. Previously, the "New case" option did not reinitialize fields correctly under those conditions.
June 30, 2013:
Time for one more this month: Word Grid - Complete 3 Letter Words, to solve, or at least help solve, puzzles such as this one. Insert a 6 letter word into the top row of a 6x3 grid to form 6 three letter words in the vertical columns. Oh, and for this particular puzzle, the missing word must be a bird species.
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