Sudoku

[Surfingfarmboy]

Re: Sudoku

Scrivener, in post #10, provided interested viewers links to other Sudoku puzzles. Link #1 leads one to 2 individual puzzles..the page with art of peacock shedding fly-away hearts.

I printed it out, and completed the first one with relative ease.

My questions are:

1. Do these particular puzzles have any difficulty ranking? I'm just curious about their difficulty factor, seeing how easily I finished the first one.

2. What do the two boxes with "sub-squares" contained with them indicate? Both puzzles have this common between them.

[scrivener]

Re: Sudoku

1. Do these particular puzzles have any difficulty ranking? I'm just curious about their difficulty factor, seeing how easily I finished the first one.

As a matter of fact, they do. Puzzles from Oekaki King are rated on a scale of one crown to five crowns. You can see the crowns in the circle containing the puzzle number. Puzzles from Logic Paradise are rated from one to ten stars, and the stars are also in the circle containing the puzzle number.

It should be pointed out that these publications aren't Sudoku magazines--they actually feature another brand of mathematical logic puzzles called Paint by Number, Nonograms, or Griddlers (all names referring to the same type of puzzle), so the difficulty rating is actually in comparison to other puzzles in the magazine, not other Sudoku puzzles. The puzzles in the Star-Bulletin rate the puzzles from one star to five stars, and this is probably a truer evaluation of their relative difficulty.

2. What do the two boxes with "sub-squares" contained with them indicate? Both puzzles have this common between them.

Puzzle magazines in Japan are huge business, and one way publishers attract readers is by offering prizes for correctly solving the puzzles (the prizes are quite impressive). In the case of the Nonograms, the completed puzzle forms a picture, so puzzlers in Japan are given an answer sheet with blanks, and they simply write in the blanks what each puzzle is a picture of.

With these Sudoku (referred in every Japanese magazine I've seen, by the way, as Number Place and not Sudoku), I believe the little sub-squares are target squares. Puzzlers add up the numbers in these squares and provide their sums in the answer blanks. They have nothing to do with the actual puzzles, so don't be distracted by them.

I'm glad you enjoy them! Let me know if you ever need more!

[Surfingfarmboy]

Re: Sudoku

Thank you Scrivener, for the explanations!!

I love these now...I'm hooked. I'm hoping when I'm in Honolulu this December to see if I can buy some puzzle magazines imported from Japan that specializes in the Sudoku puzzles, such as Oekaki King, or whatever ones I can find. I may not be able to understand what the mags have written in them; just as long as there are the puzzles in them that are in the form that I'm learning to deceipher, I'll be okay. I remember once, in a HT trivia game, you made reference to a bookstore that specializes in printed matter from Japan. Could this establishment be potential source for these puzzles?

I am only going to attempt to solve puzzles that I've legitimately obtained from now on. I've come to the conclusion that puzzles that one doesn't obtain properly, i.e., "dey wen kakaroach", are by the cosmic powers around us, deemed unsolveable by the person doing the purloining.

I "borrowed" the section from the daily newspaper here that has started recently printing the Sudoku puzzle, from the lobby of a quick-change oil garage yesterday. I mean, they had 3 copies of the paper in the lobby, and it was late in the day, so who was going to miss it, right? I took it home, spent way too much time on it last evening, and never got around to solving it...I made a mistake somewhere that, of course, made solving the puzzle, unsolveable. A case of bachi, perhaps? Karma? I learned my lesson...I will only solve puzzles I've outright bought, or ask permission if I can have the section of paper that has the puzzle in it! I'm convinced there is NO solving them if I don't!!

[Surfingfarmboy]

Re: Sudoku

I have been trying to solve a 4 star rated Sudoku, and I have come to a complete halt in solving it, due to a situation that I can't find a strategy to continue with.

After filling in all of the easy and obvious numbers, I've run into a situation where the authors of this puzzle have intentionally made it difficult to go on. They have paired up two numbers that can, when all of the other obvious numbers have been placed, and when following the logic of the puzzle, both be in the same square of a grid..I can't eliminate one or the other through logic. It's one of those situations where I cannot eliminate or definitively say that a number I need to place or not place can go into/not go into a particular square, or grid, even when I bring in a third or fourth number in an attempt to find a solution, as all of the arguments I've presented to myself in trying to place these numbers are true or negative for both numbers, i.e., the same criteria for the number 2 hold valid for number 3.

What is the next advanced strategy for place numbers like this, when there are no obvious clues left? I couldn't quite follow the Wikipedia explanation beyond the scanning portion.

[scrivener]

Re: Sudoku

I can't eliminate one or the other through logic. It's one of those situations where I cannot eliminate or definitively say that a number I need to place or not place can go into/not go into a particular square, or grid, even when I bring in a third or fourth number in an attempt to find a solution, as all of the arguments I've presented to myself in trying to place these numbers are true or negative for both numbers, i.e., the same criteria for the number 2 hold valid for number 3.

Hey surfingfarmboy, did you ever finish this one? If not, I'd love to take a look at it. Just write the digits in order from upper left to lower right, saying "space" for an unknown.

[scrivener]

Re: Sudoku

Did anyone try the Sudoku variations I posted links to? Just curious. I'd love to know what you thought of them.

[Surfingfarmboy]

Re: Sudoku

Hey surfingfarmboy, did you ever finish this one? If not, I'd love to take a look at it. Just write the digits in order from upper left to lower right, saying "space" for an unknown.

Funny you asked that! No...I lost it! I lost it on the recently completed journey to Chicago. I had every intention of completing the puzzle..or at least giving it a shot, but somewhere, between PVD and ORD, I lost it...lost the mechanical pencil I was solving it with too. Anyway..that one was rigged to be a touch walnut to crack. There were so many numbers that could logically be played in the open squares. I'm pretty sure this puzzle could only be solved with a logic I haven't yet fomulated, let alone mastered, in the Sudoku puzzledom.

I have played the easier puzzles you've linked to. I'm going to give the over-lapping "Tri-Sudoko"..the 3 sudokus super-imposed over each at some point. (I have printed it up.)

I'm kind of leery about the < > varieties. Those look like they could be really frustrating!

[Surfingfarmboy]

Re: Sudoku

I guess I'm officially hooked on Sudoku. I bought my first Sudoku puzzle book yesterday, which bills itself as the "Offcial Publication of the International Sudoku Authority"..the "ISA". The small booklet, published monthly, has puzzles rated very easy to very hard, and like its Japanese counterparts, it also offers cash and prizes to entries, solved from the booklet, that are registered online. (Top prize is $1,000)

Appears there's no turning back for me now!

[damontucker]

Re: Sudoku

This past Sundays Starbulletin 1/15/06 had a "Universal Sudoku Monster)

Instead of the usual 9 boxes, it had 12.

Besides filling in 0-9 you also had to fill in the Letters A - F.

I can't even do the 9 box one... I just can't imagine people racking there brains on this 12 box one.

[Moto]

Re: Sudoku

If you can't get enough of Sudoku's you can play them online at websudoku.com. They have puzzles ranging from easy, medium, hard and evil. Some of the evil ones are exactly that. Enjoy

[Surfingfarmboy]

Re: Sudoku

I went to www.websudoku.com and it is blast! If you're another Sudoku addict looking for some more puzzles, I recommend giving this site a visit.

[scottsportshawaii]

Re: Sudoku

Sudoku is almost as addicting as Jack Bauer and 24!

Mahalo,
Scott
www.sportshawaii.com
"Hawaii's Fan Based Sports Page"

Previous Sports Angel: Midori

[Surfingfarmboy]

Re: Sudoku

About Sudoku: How do the creators of a specific puzzle know that it can be solved logically and without guessing, through the numbers given? Is it possible to create a Sudoku puzzle that cannot be solved logically..the numbers given will not allow for any logical conclusions?

[scrivener]

Re: Sudoku

I know that one Sudoku publisher, Conceptis, has a computer that runs an algorithm designed to test for difficulty level, solvability, and uniqueness of solution.

There are certain variables that give these results, such as the number of times one numeral appears in the given clues, or the number of given numerals per row, column, or box. I don't know exactly what they are, but that's why puzzle-makers aren't about to divulge their alglrithms to just anyone.

I have given my students assignments to create these puzzles, but it is more difficult than it seems, especially to create a puzzle that isn't a cake-walk and has a unique solution.

I don't know if you've noticed this, but many of the puzzles have a certain aesthetic about them: either the given numerals are arranged in a cool pattern when you begin, or there are no given 9s, or the numerals given in any particular box add up to the same sum. This comes largely from the Japanese part of Sudoku's history, where puzzle magazines are huge business. There are, in fact, puzzle-writing schools, where people learn to create aesthetically pleasing puzzles of varying difficulty.

It is definitely possible to create an unsolvable puzzle, one with more than one legal solution, but a puzzle with no legal solution seems impossible. If you have five open squares left, for example, the rules of the puzzle dictate that there can only be five exact numerals to place in these squares. These five may yield more than one legal solution, but if they yield no legal solutions, there has to be an illegally placed numeral somewhere else in the puzzle.

[Surfingfarmboy]

Re: Sudoku

I have noticed the patterns evident within the Sudoku grids, similar to the way creators of crossword puzzles make mirror images of the patterns found in those puzzles in two equally spaced areas within the gaming grid.

One thing I've noticed I've done a lot in Sudoku solving is to solve for the obvious and easiest clues first for some puzzles, which often times, if done to the puzzlemakers plan, will lead to another completed pattern, such as two completed lines going horizontally and two completed lines going vertically, or numbers appearing in the same spots of 4 equidistant squares, and so forth. Then at that point, I find that I've been suckered...I've completed the easiest part of the puzzle, now the hard part in figuring it out completely, often times with no easily ascertained clues, is the next step. It's almost as if the creators are lulling a player into thinking a puzzle is going to be a cinch, then all of a sudden, it turns into, as websudoku.com calls them, an "evil" puzzle.

That web-site Conceptis you've linked to looks like it has some real logic game doozies. I don't think I'm anywhere near ready to attempt some of the games they have beyond Sudoku. I'm still working on cracking an evil Sudoku.