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Guest Guest

Posted: Sat Jan 21, 2006 10:17 pm Post subject: Where are the solutions? 


I can't seem to locate the solution to the Sudoku's on this site. Where are they? 

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Guest

Posted: Sat Jan 21, 2006 10:25 pm Post subject: 


Opps! Never mind found them. I was getting ahead of things. 

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Guest

Posted: Sun Jan 22, 2006 12:13 am Post subject: 


Why worry about solutions?
The attraction of Sudoku is in the solving  with that wonderful
paradox that the goal (finding the right digit to be in each of the
81 cells) is totally irrelevant once attained. A solved Sudoku has
no intrinsic worth  unlike an UNSOLVED one which carries with it
the challenge of a solution yet to be unhidden.
Checking off one's own solution against the published one is boring!
What matters is that one's solution obeys the rules and that each
row, column and region has all nine digits. That is all that is needed!
Even getting the solution for a single cell part way through the
process of solving is of no real value. One needs to know "why?"
a digit has to be in a particular position. That is the value of the
excellent service provided by our Friends from Colorado and
Munchen  they provide explanations! I fail to understand how they
can keep up that service day after day  they are clearly addicted
to serving the rest of us, and long may that continue!
Alan Rayner BS23 2QT 

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someone_somewhere
Joined: 07 Aug 2005 Posts: 275 Location: Munich

Posted: Sun Jan 22, 2006 8:17 am Post subject: 


Hi Alan,
If you would be a girl, I could get in love with you.
We have the same understanding of Sudoku.
Looking always for a puzzle that puts new problems for solving it!
How we solve it  that's the fun.
still alive, 

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StoneLouisville Guest

Posted: Sun Jan 22, 2006 4:14 pm Post subject: Help with Today's Puzzle 


Hi,
This is my first time on the site and I need some help with the Jan 22 puzzle. I'm just starting these puzzles and I must say they are addictive. Here is what I have so far which isn't much:
504 090 000
093 002 000
286 003 409
020 600 094
961 000 700
430 009 060
050 800 970
040 900 530
009 050 842
I put 0's for blanks. My question is this: why does a 2 have to go in r7c3, why can't it go in r8c3? The hint from the site gave me the r7c3 answer, but I don't know why. 

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David Bryant
Joined: 29 Jul 2005 Posts: 559 Location: Denver, Colorado

Posted: Sun Jan 22, 2006 6:48 pm Post subject: Re: Help with 22 Jan '06 puzzle 


StoneLouisville wrote:  ... why does a 2 have to go in r7c3, why can't it go in r8c3? The hint from the site gave me the r7c3 answer, but I don't know why. 
Hi, StoneLouisville! Welcome to the forum.
If you examine column 3 you will find {1, 3, 4, 6, 9} entered there. Looking at row 7 you will see (5, 7, 8}. That's eight distinct digits. So the only one left that can possibly fit at r7c3 is a "2".
This situation arises in sudoku puzzles quite often. We call this situation "sole candidate"  "2" is the sole candidate for r7c3 because it's the only value that can possibly fit there.
Happy Solving! dcb 

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bette
Joined: 22 Jan 2006 Posts: 6 Location: Fredericton, NB Canada

Posted: Sun Jan 22, 2006 9:18 pm Post subject: Re: Help with 22 Jan '06 puzzle 


David Bryant wrote:  StoneLouisville wrote:  ... why does a 2 have to go in r7c3, why can't it go in r8c3? The hint from the site gave me the r7c3 answer, but I don't know why. 
Hi, StoneLouisville! Welcome to the forum.
If you examine column 3 you will find {1, 3, 4, 6, 9} entered there. Looking at row 7 you will see (5, 7, 8}. That's eight distinct digits. So the only one left that can possibly fit at r7c3 is a "2".
This situation arises in sudoku puzzles quite often. We call this situation "sole candidate"  "2" is the sole candidate for r7c3 because it's the only value that can possibly fit there.
Happy Solving! dcb 
I figured this part out, but the hint is telling me that 4 goes in r3c7. Why can't 4 go in r2c7?
Bette 

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David Bryant
Joined: 29 Jul 2005 Posts: 559 Location: Denver, Colorado

Posted: Mon Jan 23, 2006 12:42 am Post subject: Why there's a "4" at r3c7 


Bette wrote:  I figured this part out, but the hint is telling me that 4 goes in r3c7. Why can't 4 go in r2c7? 
Hi, Bette! Welcome to the forum.
Generally speaking, it would be helpful if you could post your position when you're asking a question. In this case I gather you're pretty close to the start of the puzzle. Before you can place a "4" at r3c7 you have to make two moves, both of which are pretty obvious.
1. r3c1 = 2 (This is the only place a "2" can fit in top left 3x3 box.)
2. r9c8 = 4 (This is the only place a "4" can fit in bottom right 3x3 box.)
Now the puzzle looks like this:
Code:  5 . 4 . 9 . . . .
. 9 3 . . 2 . . .
2 8 6 . . 3 . . .
. 2 . 6 . . . 9 4
. . 1 . . . 7 . .
4 3 . . . 9 . 6 .
. . . 8 . . 9 7 .
. . . 9 . . 5 3 .
. . . . 5 . 8 4 2 
Let's think about the values that can possibly fit at r3c7. We already have {2, 3, 6, 8} in row 3, and we have {5, 7, 9} in column 7. So the only values that can possibly fit at r3c7 are "1" or "4"  the other seven values are already used up, as "peers" of this cell.
Now concentrate on column 8 and ask yourself where can a "1" be made to fit? Clearly it can't go at r5c8, because of the "1" at r5c3. So it has to go in the top right 3x3 box somewhere, either at r1c8, r2c8, or r3c8. (Actually, it can't go at r1c8, but that's kind of hard to see, so let's not get into that right now.)
Anyway, the point is that the "1" in the top right 3x3 box has to fit in column 8 ... otherwise we can't possibly put a "1" in column 8. But if the "1" in the top right 3x3 box is in column 8 it can't be at r3c7. So the only value we can put at r3c7 is a "4". dcb 

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