The New Sudoku Players' Forum

[JanNewburgh]

Can someone help me solve the Washington Post puzzle Number 59, published on Saturday, Jan. 15? I'm stuck, even when I use dyads and triads! Thank you.

[Crazy Girl]

JanNewburgh

Can you post the puzzle, and where you have got to, including the pencilmarks for each cell to show what numbers can go in each cell, so that we can understand what you have done and what you have missed.

[QBasicMac]

Is this what you are working on?

Code: Select all

--3  6-8  --9
---  ---  -21
---  ---  ---

2-8  -9-  -57
--6  -2-  8--
41-  -7-  2-3

---  ---  ---
57-  ---  ---
8--  3-4  6--


(Jan 15 WashingtonPost.com)
http://www.uclick.com/client/wpc/wpdoc/2006/01/15/index.html

There is no need for triads and diads. This puzzle solves easily with singles.

Example: row 4 col 2 is a 3 because only box 4 candidates 3579 could go there and 7 is already in col 2 and 79 is already in row 4.

What am I missing here?

Mac

[JanNewburgh]

Thank you for your help. This is my first experience with the Players' Forum. The puzzle is labeled as hard. Can you tell me the best way to post where I am on the puzzle? I'll try to put what I have so far, below. I'm sure you can tell me a better way to post what I've done. Thank you.

5 7 3-4 9 2 8 6 1 3-4
4-6-9 4-6-9 8 3 1 4-6 2-7 5-7 2-5
1 3-4-6-9 2 5 7 4-6 8 3-9 3-4-9

3-4-7 5 4-7 8 3 9 2-7 6 1
7-9 1-9 6 2 5 1-7 3 4 8
8 1-2-3 1-3-7 6 4 1-7 9 5-7 2-5

2-6-9 2-6-8-9 5 4 6-8 3 1 2-9 7
2-3-6-7-9 1-2-3-6-8-9 1-3-7-9 1-7 6-8 5 4 2-3-9 3-9
3-4-7 1-3-4 1-3-4-7 1-7 9 2 5 8 6

[QBasicMac]

Actually, you have some eliminations that I can't follow. Let's start over with this:

Code: Select all

+---------------------+------------+----------------+
| 5      7       34   | 9   2   8  | 6   1     34   |
| 469    469     8    | 3   1   46 | 27  2579  2459 |
| 1      3469    2    | 5   7   46 | 8   39    349  |
+---------------------+------------+----------------+
| 247    5       47   | 8   3   9  | 27  6     1    |
| 79     19      6    | 2   5   17 | 3   4     8    |
| 8      123     137  | 6   4   17 | 9   257   25   |
+---------------------+------------+----------------+
| 269    2689    5    | 4   68  3  | 1   29    7    |
| 23679  123689  1379 | 17  68  5  | 4   239   239  |
| 347    134     1347 | 17  9   2  | 5   8     6    |
+---------------------+------------+----------------+


First see that row 8, column 3 (r8c3) is {1379}.
But that is the only 9 in column 3, so we can make r8c3=9.
That is called "Hidden single 9 in col 3"

Ok, you also have Hidden single 9 in row 7 (because by placing r8c3=9, you can erase the 9's from the first two cells (269 2689) --> (26 268) and thus there is now only one 9 in row 7.

Then r3c8 = 3, etc.

Just keep going like that. You can do it.

Mac

P.S. If you know how to use ZIP files and directories (folders), you may find my program SSP3 at www.Sudoku.funURL.com useful.

[Cec]

"..I'm sure you can tell me a better way to post what I've done..."

Hi Jan,

Click on THIS THREAD which explains how to post puzzles.
Make sure you have the "Code" tags correctly inserted at the start and end of your puzzle as follows but using these brackets [ ] instead of these ( )

(Code)
Insert puzzle
(/Code)

Cec