The New Sudoku Players' Forum

[tso]

Yeah, that didn't come out right. I meant that I thought the article was great. There were several variants I hadn't seen before. And I was especially intrigued by those and I am especially interested in the 12345 nanpure and 1234 nanpure as I had wondered if that type of puzzle would work.

Figuring out *how* to solve each puzzle is really the only part that holds my interest. Those seem most promising.

[Pat]

has anyone tried the Sudoku Hexagon (2005.Sep.11 at The Daily Mail)?

[lmc]

Hi, yes I've tried it. Were the rules given anywhere? I assumed that each set of triangles joined by circles had to contain numbers 1-6, as did the set of 6 with filled circles and the set of 6 with open circles. It seemed to complete OK that way.

[tso]

Here's a nine year old web page with five COLOR NUMBER PLACE puzzles.

1) Each row, column and box must contain one of each digit.

2) Each digit must appear exactly 3 times in each color.

3) Each color must appear exactly 3 times in each row, column and box.

I have not attempted to solve them -- I am colorblind. The red and the green are nearly indistinguishable.

[udosuk]

Clarification of the rules:

According to the source, there are a total of 4 rules:

A: All rows and columns contain the digits 1-9.

B: All 3x3 blocks contain the digits 1-9.

C: Within all 3x3 blocks, each mini-row (1x3) and mini-column (3x1) must contain 3 different coloured digits (1R, 1G, 1B).

D: Within all 3x9 horizontal bands and 9x3 vertical stacks, the same digit must be in 3 different colours (1R, 1G, 1B).

Rules A+B are standard sudoku rules and is equivalent to rule 1 of tso.
Rule C implies rule 3 of tso, though not vice versa.
Rule D implies rule 2 of tso, though not vice versa.

As for tso's colourblindness difficulty, you could still crack at these puzzles if you're willing to spend some time and effort. Just save all the pics in the web page (they're all 4-bit coloured png files sized <10kB each).

Now use a little windows accessories program called "Paint" to open them. You'll see a palette (color box) with only 16 colors. The 3 colors used (R, G, B) are respectively the 3rd, 5th, 7th palette squares in the bottom row of 8.

So just pick say, the red colour and use the "fill with color" tool to fill all the cells with R/G digits that you couldn't distinguish. Next pick the white colour and repeat the same process. Naturally all red digits will be wiped out and all that's left must be the green ones.

Now compare this to the original pic and you can spot the red digits. This time you could fill around the red digits with a yellow or gray background and voila, all 3 colours of digits could be easily distinguished now!

Also, seeing I could be the only one in this forum with some ability to read/understand Japanese, if you have doubt about rules of other Japanese puzzles, feel free to list them, I could help you clarify more. Ta.

[tso]

That's for the rule correction. I'll keep the translation offer in mind.

[udosuk]

"That's" alright.

I think a quick & dirty resolve for your colour blindness is to use "Invert Colors" (Ctrl-I) in Paint. Of course that would turn the background totally black and make some other digits harder to see. Then you might still need to fill all the cell space with yellow or gray to get a good view. But I guess the best solving tool for this kind of puzzle would be Excel where you could easily change the font/background colour of each cells by 1-2 clicks... to whatever colours you like/can distinguish.

I think Micro$oft should be thinking of the colour blind users when they serve up those Accessibility features, perhaps a function to change the whole palette of red/green to another colour?

(Sorry I should not assume you use Windows... and I'm not surprised if it happens that you don't... then all my suggestions are pointless.)

[tso]

Many variants are given here:

http://www.maa.org/editorial/mathgames/mathgames_09_05_05.html

This was a very popular article. There is some follow-up here:

http://www.mathpuzzle.com/

Lots more variations with good descriptions here:
http://www.mathpuzzle.com/Sudoku/WeiHwaSudoku.htm


udosuk -- Thanks for the colorblindness suggestions. I should have mentioned that I'm able to workaround most color problems -- it's just annoying. Since there are always plenty of other choices of problems to work on, I tend to ignore those with color. I have a conjecture that I can only support with anecdotal evidence that those of us who are colorblind take our cues less easily from color, even when the colors involved are easily distinguishable because of years of negative reinforcement.

[r.e.s.]

I have a conjecture that I can only support with anecdotal evidence that those of us who are colorblind take our cues less easily from color, even when the colors involved are easily distinguishable because of years of negative reinforcement.

Yes, I think that's right (I'm red-green colorblind myself). It's very apparent if I play tile games (e.g. solitaire Maajong) with tiles depending on color- or brightness-distinction (with colors and/or brightnesses that I can distinguish well) -- definitely harder than if I play with tiles depending on shape-distinction. Sudoku without shape-distinctions would drive me nuts!

[udosuk]

Yes, I think that's right (I'm red-green colorblind myself). It's very apparent if I play tile games (e.g. solitaire Maajong) with tiles depending on color- or brightness-distinction (with colors and/or brightnesses that I can distinguish well) -- definitely harder than if I play with tiles depending on shape-distinction. Sudoku without shape-distinctions would drive me nuts!

Being a veteran player of the marvelous game of Mahjong, I don't think Mahjong tiles are depending on colour/brightness at all, not in the normal game or any solitaire mini-game versions... They are totally distinctive in shape. You must have been confused with Uno cards or Rummikub etc. I think you'd be more annoyed that you couldn't identify the Chinese characters in some Mahjong tiles than about their colours layout.

And seeing we already have 2 RG colour blind members in this place, could there be a conjecture that RG colour blindness is related to the enthusiasm/talent in sudoku puzzles?

[r.e.s.]

I don't think Mahjong tiles are depending on colour/brightness at all, not in the normal game or any solitaire mini-game versions... They are totally distinctive in shape.

As a veteran player you may know of Kyodai Mahjongg, for which there are many tilesets available in which some tiles differ only by color, not shape. Many people play at least occasionally with some of the zillions of "nonstandard" tilesets, of course.

And seeing we already have 2 RG colour blind members in this place, could there be a conjecture that RG colour blindness is related to the enthusiasm/talent in sudoku puzzles?

More likely that's due to this form of colorblindness being so commonplace.

[udosuk]

Alright, I meant to say I'm a veteran player in the formal mahjong game, where 4 people sit around a square table trying to make hands and win big money... not the solitaire spin-offs.

After some researching now I know Kyodai is a software that gives users the choice of tilesets, music etc. to play those solitaire games. I'm not addicted to the solitaire games that much to want to try that particular software and its amazing features anyway... Can't see the big difference playing the game in another tileset when the rules are exactly the same. Maybe it'll give thrills to those who had played the game with the original tileset for thousands of times...

Anyway an alternative for the CB people to play that "Colour Number Place" game is to use Excel to play it, but replace the different colouring features to bold, italic, underline, etc. But an effort is still needed to reproduce the puzzles in that format...

[PaulIQ164]

Hello! I think this topic should be moved to the Variants forum. Then pinned, because it's so comprehensive and great.

[CathyW]

I'll second that! I didn't realise there were quite so many variants.

Having seen the "Sum Doku" (a.k.a. Killer Sudoku) which is my favourite variant (so far!) I wonder if we should try and persuade the Times to change the name. "Sum Doku" is a much nicer and more accurate description.

[PaulIQ164]

Thanks, invisible yet bounteous sir admin.