Calcudoku puzzle forumhttp://www.calcudoku.org/forum/ My new puzzleshttp://www.calcudoku.org/forum/viewtopic.php?f=16&t=366 Page 1 of 2

 Author: giulio  [ Thu Nov 15, 2012 6:44 am ] Post subject: My new puzzles When I realised that I was waiting for Tuesdays to solve the "pattern" CalcuDokus, I decided it was time to try to make my own. You might remember that I published time ago a book of Double CalcuDokus and one of Samurai Calcudokus. You might also rmember that I developed a web page with daily CalcuDokus. The controls to solve them online were not the most efficient and somebody (sorry, don't remember who) that my puzzles were of average difficulty.Anyhow, I thought I had most of what I needed to develop pattern CalcuDokus, and so I started working on them. To modify the program I had was easy enough (I only develop 9x9 puzzles), but it turned out that to find the right patterns was not!We two of the patterns I tried out, my program didn't converge at all. It tried for hours, but it didn't makaneg to generate a single puzzle. In case you are curious, here they are:These patterns consists of "islands" of cages that form separate "sub-puzzles". Especially the first one. That's why no unique solution could be found (I believe). It makes sense that a unique solution is only possible if there are enough crossings.Some patterns, like the two following ones, converge quickly to puzzles with unique solutions:Then, with some patterns, my program requires many minutes to produce a puzzle. Here is an example of such a pattern:I also found that the pattern CalcuDokus tend to be more difficult than the "unorderly" ones.Anyhow, I started working on a book of pattern CalcuDokus. But I wanted to be sure that all puzzles could be solved analytically. Unfortunately, the only way I have found to identify analytically solvable puzzles is to actually solve them. I know, if I cannot solve them, they can still be solvable... For example, I fail to solve perhaps half of Patrick's Tuesday puzzles. And yet, I don't think I am a bad solver, although definitely not a fast one.In any case, to write my book, I started generating pattern puzzles and solve them. Sometimes I made mistakes and had to start from scratch. Some other times, I got stuck and had to give up after struggling for hours. Here is an example of a puzzle that IMO requires guessing. Tell me whether you can solve it analytically. I cannot:After days of solving puzzles, I realised that I was getting saturated. That's why I decided to write a book with 60 random puzzles and 40 pattern puzzles (because I am confident that the random ones are analytically solvable without actually having to solve them all). I had to stop. The book is availbale from Lulu in print (http://www.lulu.com/product/paperback/200-challenging-calcudokus/20484581) for 10 Australian Dollars or from Smashword (http://www.smashwords.com/books/view/255167) in several digital formats for US\$1.99. Sooner or later, it will also be available from Amazon, Barnes & Noble, etc.Ciao, Giulio.

 Author: pnm  [ Thu Nov 15, 2012 10:28 am ] Post subject: Re: My new puzzles hi Giulio,thanks for the post/advert yes: typically, the more "regular" the patterned arrangement, the morelikely it is the puzzle will have permutations (of the numbers) that arealso valid solutions. You need to have "interlocked dependencies" (whatto call them) to get puzzles with a single solution.Good luck with the book. I would change the description though: now,on the Lulu page it says "CalcuDokus, introduced in 2004 as KenKen® (a registered trademark of Nextoy LLC), is a 9x9 numeric puzzle similar to Sudoku. But, unlike Sudoku, CalcuDoku doesn't require you to learn complex strategies."There is no need to mention "kenken" and the trademark bit.Also, the puzzle was originally called "Kashikoku Naru" (but maybe you meant "introduced in the US").And, as you know, Calcudoku is not always a 9x9 puzzle. Next we can discuss "doesn't require you to learn complex strategies" ??? "Unlike Sudoku" ??Finally, I prefer "Calcudoku" over "CalcuDoku", but that's just my personal preference Patrick

 Author: giulio  [ Thu Nov 15, 2012 12:53 pm ] Post subject: Re: My new puzzles Hi Patrick,Thanks for the good wishes, although, I have to admit, I have given up to making any reasonable/substantial/significant/non-negligible (take your pick) amount of money with these books of puzzles!Quote:There is no need to mention "kenken" and the trademark bit.Yes, but why not? If people search for KenKen and I don't mention it, they might not find me.Quote:Also, the puzzle was originally called "Kashikoku Naru" (but maybe you meant "introduced in the US").I don't doubt that you are right, but I suspect that most people are as ignorant as I am! Quote:And, as you know, Calcudoku is not always a 9x9 puzzle.Of course, but: if people know it, they will notice that I only speak of 1-to-9 numbers and will understand that the book only includes 9x9s; if people don't know it, as I only generate 9x9, why should I care to tell them? Quote:Next we can discuss "doesn't require you to learn complex strategies" ??? "Unlike Sudoku" ??Well, I started solving CalcuDokus after solving lots of Sudokus, learning all possible strategies, and writing about them. Most of Sudoku's strategies rely on the fact that unicity is enforced on rows, columns, and boxes. In CalcuDoku there are no boxes. This at once eliminates complex Sudoku strategies like Swordfish. I find that with CalcuDokus you need to think logically, but the strategies are simpler.Quote:Finally, I prefer "Calcudoku" over "CalcuDoku", but that's just my personal preferenceI like words with capitals in the middle! Please,feel free to keep writing Calcudoku, I won't hold it against you!

 Author: giulio  [ Wed Nov 21, 2012 1:38 am ] Post subject: Re: My new puzzles Hi clm,Congratulations! The two rows you provided match those of the solution I have. This is the solution given by my program, because I was not able to solve the puzzle myself without guessing, although, the distinction between "exhaustive and hard analysis" and trial and error is sometimes difficult to make. I always solve the puzzles with pencil, after printing them. I am fine as long as I can use the margins for analysis and write in the cells the combinations, but if the decision tree becomes very large, like in this puzzle, and I am unable to keep track of all the possibilities on the single page of the puzzle, I arrive to the conclusion that the puzzle cannot be solved analytically and give up (because I don't want to guess).I tried to solve this puzzle twice and got stuck both times...With the program that generates "random" puzzles (i.e., without patterns), I can set the maximum number of single-cell cages. Although I normally set it to 3, the resulting puzzles are not too difficult. It is not unusual the the generated puzzle only has one single-cell cage. I really think that the difficulty of the pattern CalcuDokus is due to the fact that there is a pattern.

 Author: giulio  [ Wed Nov 21, 2012 3:56 am ] Post subject: Re: My new puzzles As today calcudocu.org dindn't publish a 9x9, I generated a puzzle with the same pattern clm commented on. I wanted to see whether it would also be too difficult [for me] to solve analytically. Here it is:It turns out that it is well solvable analytically. Quite gratifying! The only problem was that my program took 27 minutes to converge to a unique solution...

 Author: clm  [ Wed Nov 21, 2012 4:19 pm ] Post subject: Re: My new puzzles giulio wrote:As today calcudocu.org dindn't publish a 9x9, I generated a puzzle with the same pattern clm commented on. I wanted to see whether it would also be too difficult [for me] to solve analytically. Here it is:...It turns out that it is well solvable analytically. Quite gratifying! The only problem was that my program took 27 minutes to converge to a unique solution... Yes, it must a be problem, 27 minutes !!! … it looks too much … you should revise your program … the solution took me around 25 minutes (same as you, in general I also like to do the big puzzles with pen and paper though in this case it's mandatory ). Now, seriously, in my opinion this second puzzle is parsecs away from your first proposal, and I am very surprised at it because the pattern is the same but this second one is quite “easy”, in fact I think it’s more or less as the normal 9x9’s in calcudoku.org (and much easier than the ones on tuesdays). The reason could be: In the first puzzle we only had one number initially defined (the 3 in e5, apart of the 9 of row 5 in d5, and consequently the 1 in d6, analytically deduced because the 9 can not be an operand in the cages involving row 5, that is, “336x”, “2:” and “160x”). But in this puzzle we have several numbers “virtually” placed (with very little analysis): b3 = 5, b4 = 1, c4 =5 >>> “7-” = [2,9]; since a 5 must be in f2 or g2 >>> i1 = 5, i2 = 8. The cage “2160x” has the only possible combination [5,6,8,9] then i6 = 6 and g5-h5-i5 = [5,8,9]. Also e6 = 5 (the only available position for a 5 in column “e”) and now in column “a” the 5 must go to “7+” = [2,5] since there is a 5 in every row from 1 thru 6 and a 5 is not a factor of “864x” … . Also the 1 of row 6 must go to d6 (unique since now f6 is not valid and the 1 is not an operand in “864x” or “96x”) >>> d5 = 3 >>> c8 = 3 >>> d7-d8 = [5,7]. Obviously “5+” (f4-f5) = [2,3] with f4 = 3, f5 = 2 (due to a 2 present in d4-e4 which is equal to [2,9]) (the combination [1,4] is invalid for “5+” since it would make impossible the cage “64x” that has [1,2,4,8] as the only valid combination with two lines), etc. … suddenly many numbers are defined; the rest of the combinations are reduced quickly … (btw, the other three “perpendicular” cages “3:” facilitate the solution, etc.).(For reference, row 7 of my solution: 639714582)

 Author: clm  [ Wed Nov 21, 2012 4:25 pm ] Post subject: Re: My new puzzles Hi giulio, apologize for giving a row of the solution in my previous post, too early .