The New Sudoku Players' Forum

[NoClue]

Hi, all,

Here is a 32-clue Sudoku, which I couldn´t solve. (difficultiy is: "very hard" # 648929)
|2 . .|

Code: Select all

+-----+-----+-----+
|. . 7|4 2 .|. 6 .|
|2 . .|. 8 5|. . .|
|. . 3|. . 9|4 . 2|
+-----+-----+-----+
|. 4 5|. . .|. . 1|
|9 8 .|. . 4|. 5 3|
|7 . .|. . .|8 9 .|
+-----+-----+-----+
|4 . 8|9 . .|2 . .|
|. . .|7 3 .|. . 6|
|. 7 .|. 4 2|9 . .|
+-----+-----+-----+

I hardly found hidden singles (only 20) - so I had to do pencilmarking (29 cells!):

Code: Select all

+-----------+-------------+---------+
|8.. 159 7..|4.... 2.. 13.|135 6. 59|
|2.. 169 4..|136.. 8.. 5..|13. 17 79|
|156 156 3..|16... 7.. 9..|4.. 8. 2.|
+-----------+-------------+---------+
|3.. 4.. 5..|8.... 9.. 7..|6.. 2. 1.|
|9.. 8.. 126|126.. 16. 4..|7.. 5. 3.|
|7.. 16. 126|12356 156 136|8.. 9. 4.|
+-----------+-------------+---------+
|4.. 3.. 8..|9.... 156 16.|2.. 17 57|
|15. 2.. 9..|7.... 3.. 8..|15. 4. 6.|
|156 7.. 16.|156.. 4.. 2..|9.. 3. 8.|
+-----------+-------------+---------+

I need a lot of tips, because I have --- LESS than no BRAIN --- LESS than NO logical understanding --- LESS than NO memory!

Any hints are appreciated! Thanks in advance

[Pat]

Here is a 32-clue Sudoku, which I couldn´t solve.
(difficultiy is: "very hard" # 648929)

Code: Select all


 . . 7 | 4 2 . | . 6 .
 2 . . | . 8 5 | . . .
 . . 3 | . . 9 | 4 . 2
-------+-------+------
 . 4 5 | . . . | . . 1
 9 8 . | . . . | . 5 3
 7 . . | . . . | 8 9 .
-------+-------+------
 4 . 8 | 9 . . | 2 . .
 . . . | 7 3 . | . . 6
 . 7 . | . 4 2 | 9 . .



after 20 "singles" --

Code: Select all


 8 . 7 | 4 2 . | . 6 .
 2 . 4 | . 8 5 | . . .
 . . 3 | . 7 9 | 4 8 2
-------+-------+------
 3 4 5 | 8 9 7 | 6 2 1
 9 8 . | . . 4 | 7 5 3
 7 . . | . . . | 8 9 4
-------+-------+------
 4 3 8 | 9 . . | 2 . .
 . 2 9 | 7 3 8 | . 4 6
 . 7 . | . 4 2 | 9 3 8



of course you do have some simple moves, e.g.

in box 3, the 5 is in row 1
-- exclude 5 elsewhere in that row

this solves the 5 for column 2

too tough for me---

[daj95376]

of course you do have some simple moves, e.g.
in box 3, the 5 is in row 1
-- exclude 5 elsewhere in that row
this solves the 5 for column 2

Where can you now place <1> in [r3] and [r9]?

[aran]

Code: Select all

 *-----------------------------------------------------------*
 | 8     19    7     | 4     2     13    | 135   6     59    |
 | 2     169   4     | 36    8     5     | 13    17    79    |
 | 16    5     3     | 16    7     9     | 4     8     2     |
 |-------------------+-------------------+-------------------|
 | 3     4     5     | 8     9     7     | 6     2     1     |
 | 9     8     126   | 12    16    4     | 7     5     3     |
 | 7     16    126   | 1235  156   136   | 8     9     4     |
 |-------------------+-------------------+-------------------|
 | 4     3     8     | 9     156   16    | 2     17    57    |
 | 15    2     9     | 7     3     8     | 15    4     6     |
 | 156   7     16    | 15    4     2     | 9     3     8     |
 *-----------------------------------------------------------*


Using Uniqueness :
16 is impossible in r3c1 r9c1 r9c3 r6c3 r6c2 r2c2.
=> SIS {9r2c2 ; 5r9c1 ; 2r6c3} (ie one of those has to be true, to avoid the deadly pattern)
But 16 is equally impossible in r3c1 r9c1 r9c3 r5c3 r6c2 r2c2
=>SIS {9r2c2 ; 5r9c1 ; 2r5c3}.
But one of 2r6c3 and 2r5c3 must be false.
And whichever, it follows that one of {9r2c2 ; 5r9c1} must be true, hence :
9r2c2=(5-6)r9c1=6r9c3-6r56c3=6r6c2 : =><6>r2c2 ste

[ronk-Moderator]

NoClue is apparently a beginner learning the basic sudoku techniques. Please keep this in mind when making suggestions.

[NoClue]

Hi, ronk-Moderator,

it is MORE than a SCANDAL, that I stay on a level, which is LESS than a 6 month old CHILD!! In January 2007 I began playing my first Sudokus. So 4 years have gone and there is NO SUCCESS, NO PROGRESS, NO DEVELOPMENT for me concerning Sudokus. NORMALLY I have to join EVERY worldwide competition - and - minimum criteria for me - to WIN EVERY of them!

But I can´t explain myself why I am more helpless than a 6 months old child, when I play Sudoku (better said: TRY to play Sudoku!). I think the subject of this thread was well considered by me. It´s the endless frustration I have every day - because I am not able to solve Sudokus without help from others. The comparision with a 6 months old child, what can´t do anything himself/herself - is very similar to my situation, when I try to solve Sudokus.

Everyone of you sees X-Wings, XY-Wings, Forcing Chains and all sort of fishes - some of you even without doing pencilmarking - I do pencilmarking until my head is aching, but I can´t follow any logical steps - I don´t see them at all...

Because of having that immense frustration, sometimes I injured myself. I meant that this would be the only chance for me to get better Sudoku skills.

I´m still frustrated because of my TOTALLY MISSING Sudoku compentence - it is like I am the only one in the whole world, who has:

LESS than NO brain
LESS than NO logical understanding
LESS than NO memory

[JasonLion]

Have you tried reading some of the web sites that explain the various techniques? Sudopedia is down right now, but SudokuWiki and SadMan Software both have good introductions to the intermediate and more advanced techniques.