Clarity Media Sudoku Minus

Some great community puzzles in the last two mags - they really add variety to the magazine so thanks everyone.

Clarity Media's Sudoku Times in Issue 5 was fun, and not too taxing, but I have drawn a blank with the Sudoku Minus in issue 6. Don't know whether I am missing something really obvious, but at the minute I can't find a way to get started. Is anyone out there able to give me any pointers? Thanks.

Hello Christine - well if you are missing something obvious then so am/was I. Like you I failed to make any progress with this on first attempt so abandoned it but your message inspired me to have another look last night so perhaps we can crack it together. Made a little prgress last night before I fell asleep and 5 mins ago I thought I had it cracked but it has just gone wrong.......grrrrrrr.

However think I am on right lines - well maybe hopefully perhaps...........

First thing I did, when initial inspiration failed me, was to list all the possible ways to make -3,-2,-1 and look at bottom left corner. Surprisingly this showed that 1 and 2 did not appear in any of the lists This meant 1 and 2 must be in the bottom two squares in the "2" column and therefore the square above must be a 5. This enabled me to almost complete the bottom left box. I then worked out all the options for 1,2,3,4 options and by elimination, logic, perspiration and inspiration finally managed to make a bit progress in the bottom right box and so on.

Given up at mo because having cracked all of the right hand boxes and almost all of the left hand ones (I was on a roll) it has all gone wrong. I'm sure you know the feeling. No more time now but will have another go later and see if I can spot my error - am encouraged by progress to believe it is possible.

An excellent puzzle so thanks to Clarity and Gareth. Good luck, Christine. Hope that helps. Let me know if you finish it.

I can't remember where I got to with this puzzle - I think I've thrown out my own printed copy that I tried it out on now because I replaced it with the shiny professional one that comes from Amazon.com each month. But I will give it another go... soon! Dan at Clarity warned me it was hard!



Edited 3 time(s). Last edit at 05/26/2010 06:06PM by gareth.

Hi Sue, well I have to admire your perseverance with the puzzle - I don't think I would have had the patience to list all the possible ways of making -3, -2, -1 but since you had a go I thought I'd do the same and you are right of course that in the bottom left hand corner there is no way to make the -2 or -3 using a 1 or 2, so I followed your lead and knowing that the 1,2 and 5 had to be in the "2" column I decided to give it a go. Well about an hour later, I thought I was going great guns, with all the left hand 3 x 3 boxes filled in and the top right one done, but when it came to the bottom right 3 x 3 box there was no way I could make the number combinations fit in! I have to admit that at this point I did have a peak at the solution to see where I had gone wrong and it was in the bottom left box. Didn't really have the heart to start all over again at that point, but at some time I will give it one more go and see if I can get any further. Anyway, I wouldn't even have got that far without your help so thanks.

What I am going to do is retain my sheet of paper with all the combinations on, so that if any other such puzzle appears again, I won't have all the working out to do again. I need to do that too with Gareth's negative number Killers now that they seem to be appearing each month!
Despite my lack of success I have enjoyed trying out this puzzle and getting the old brain cells to think in a different way.

Anyway, let me know if you ever complete it!

Hi Christine - glad that got you started anyway. I found it didn't take as long as I thought to list all the options which was a blessing. Interesting that we worked it the opp way round as the bottom right box was the next one I made a break thru on. I discovered on listing all the poss options for "1" that there were only 2 left for the top row of that box (given the 6,5,9,and 3 are already used). The options were 742 or 421 which meant 4 and 2 had to be there. I can't quite recall how I worked out the rest of box but that was the tipping point so hope that helps unstick you.

I have managed to finish it now as realised when I looked again that in my haste "on my roll" I had missed one poss option in one of the left hand boxes which then worked so hadn't gone wrong at all! Got there in the end (somehow) and am very chuffed to have done it! In fact it fell into place quite quickly once the initial 6 or so boxes had been "nearly" cracked.

Like you, would like to have another one sometime so all those lists can be re-used although will prob have lost them by then!

Enjoy Issue 7 - I've been (very very slowly!!) trying the 15x15 tonight and its just gone wrong dammit! Not surprised really ......... all that adding up to 120 bound to fail me!

Nil desperandum

Well done on cracking that Sudoku Minus Sue I am well impressed! You might even have inspired me to give it another go this evening, especially as you have provided a further clue for the right hand box....!

I was out last night so haven't tried the 15 x 15 yet, but will be giving it a go very shortly - I remember last time it seemed to take quite some time!

It is nice to be have someone to discuss the more unusual puzzles with! It does make you persevere with them a little longer than you might otherwise do! Good luck with it.

Well done, I didn't think anyone would solve it

Whilst the solving method is the same as for the 'sudoku +' and 'sudoku x' in that it requires working out and then whittling down the combinations and then applying standard sudoku solving rules, there is something about human psychology and the fact that the valid combinations for sums involving subtraction seem much less obvious than others that make it hard to solve.

'Sudoku divide' anyone?!...

Dan

Hello Dan - well I like a challenge and am glad Christine's message made me have another go. A very good puzzle, thanks.

Divide sounds interesting although less options available I imagine as factors are involved so might be a bit easier....or maybe I'm wrong and you will set another almost impossible one! I look forward to trying anyway. You and Gareth are certainly a good combination!

Well Sue, with your help I'VE DONE IT!! Strangely enough, on my first attempt I'd also noted down a wrong combination for -3 (had managed to get it to add up to -5 for some strange reason - obviously need some more practise with basic negative numbers!). Anyway, having put this right and got the bottom left box solved I moved across to the bottom right as you suggested - my opening for this box was with the 9. The 4,2 and 3 having been used earlier in the row mean that 8 and 1 were the only possible numbers left to make the 0. And so it went on ... an hour or two later (slow, I know) and I've finally got there.

So, great puzzle Dan, and although I wouldn't want this level of difficulty all the time, when I am in the right frame of mind I love a challenge (so much more satiisfying when you finally get there!) and so at some point it would be great to see another of these (am putting those combinations in a safe place). In the meantime, like Sue, I wouldn't say no to seeing what a division puzzle would be like!

Hey, Christine - so glad you did it. As you say, these really challenging puzzles are very satisfying if/when you crack them.

With a lot of mental arithmetic I have finally finished the 15x15 ......hurray. So thank you Gareth for that one, partic as it was one of my cheeky "requests". Grit, determination (and an eraser!) saw me thru eventually and loved it. I have a very annoying tendency to start to go too fast at the end when its almost there and make stupid mistakes and then think its all goes wrong - really must stop this!

A busy weekend now so prob no time for anymore for several days............

Funny you say that - I often do exactly the same when I solve Sudoku! I get towards the end of a puzzle and then I start hurtling the digits in rather than taking care, and as you say it all goes wrong at the very end.

Please do request the puzzles you'd like to see - in fact it actually helps, since it's one less thing to think about!

Yes - the final fatal hurtle!! Annoying or what....

Her's my requests then (you did ask!) .......

More Consecutives, a consec samurai star[/b] would be terrific; These are my top favourites!

Same for odd pairs;

More neg number killers ( or Clarity Media/Dan's variation )

Love the 15 x 15 and all calculoduko's

You can see where my love lies but am sure I don't speak for everyone. Sue

Suggestions! Well to my mind the magazine goes from strength to strength with its combination of old favourites and new varieties, but as Sue said you did ask for suggestions....

Firstly, I must have very similar puzzling taste to you Sue as I would like to see any or all of the puzzles you requested, most particularly a samurai star odd pair sudoku. (two satisfied customers then!)

A multi sudoku with a different variant in each box

Continuing on your 'giants' theme a full page masyu.

I haven't tried it yet, but like the look of the Xtra sudoku in issue 7 (combination of consecutive, calcudoku and jigsaw!)

Lewis's filomino puzzles are great as are Dan's ABCD puzzles.

Never used to do inequality sudoku but have grown to like these and the variations you put in.

Another fun variant which I am sure you will have seen is XV sudoku where all the neighbouring cells totalling 10 are marked with an X, and those totally 5 marked with a V.

Just a few thoughts, that's all - this is such a great magazine.

Oh and by the way, I am a "final fatal hurtler" too, most particularly on difficutt puzzles which ou have spent ages on - at that stage where everything finally starts dropping into place, you become careless!!!

Thanks for all the great feedback! I would have replied sooner but I was on holiday this week. I will make a list and make sure the next issue contains some (at least) of the above requests!

I also did the Sudoku Minus - as you say it's essentially a case of making a table of combinations and eliminating them bit by bit. I got going in the bottom-left 3x3 and worked from there. I might write a website widget to work out possibilities which could be used for this sort of puzzle and also my Killer Sudoku Pros. (and something similar for Calcudoku)