The New Sudoku Players' Forum

[leslyons]

I've picked up this game pretty quickly, and can zip through the easy puzzles, usually in less than 10 minutes, and the medium difficulty in around 10-14 minutes. But the hard puzzles have me stumped. I only know pretty basic solving techniques.

Can anyone suggest how I can learn some more advanced techniques?

Here's an example of a puzzle and how far I've gotten. I don't know how to show this, except just to type in rows and columns of numbers. In the puzzle below, I will put the "given" numbers in bold, and the numbers I've completed in regular text. Is there a better way to show this? I also don't know how to show pencil marks. Any help you can give me on how to solve the hard ones when I get to this point would be appreciated!

6-143---8
79-682---
----1---6

46--73-1-
---1-4687
-17-56-43

5---4----
1--3-8-7-
37-5618--

[vidarino]

Hi and welcome!

This page has a lot of useful hints on solving, from basic to fairly advanced.

If you use the "code" button while posting, the grid gets printed "aligned", like this:

Code: Select all

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

A good next step is trying to fit a few more 6s. Row 8 and column 8, for starters.

Vidar

[leslyons]

Thanks Vidar. I just overlooked the 6. I've got to study the hidden pairs, and X-Wing, etc. I don't fully understand, but I'm working on it. I'm sure that the advanced techniques will point me in the right direction. I appreciate the hint. One last question - to properly use the code button to get the numbers to appear in a grid, would I just click on the code button right before entering the 81 numbers?

[vidarino]

Hm, I think I should have been a bit clearer regard the "code" button. Apologies.

When you use the code button, two tags will be inserted, and everything between them will be shown in a monospaced font and laid out just like the text in the message. So you can prepare the grid in a text editor (e.g. notepad), and when stuck between the tags, it will look exactly like how you formatted it.

There's also a bit of information here.

[Hud]

I usually highlight the grid as if to copy it, then hit code.

[QBasicMac]

Get easily to here:

Code: Select all

+-------------------+--------------+-------------------+
| 6    25     1     | 4    3   579 | 2579   259   8    |
| 7    9      345   | 6    8   2   | 1      35    45   |
| 28   23458  23458 | 79   1   579 | 24579  2359  6    |
+-------------------+--------------+-------------------+
| 4    6      28    | 289  7   3   | 259    1     259  |
| 29   35     35    | 1    29  4   | 6      8     7    |
| 289  1      7     | 289  5   6   | 29     4     3    |
+-------------------+--------------+-------------------+
| 5    28     289   | 279  4   79  | 3      6     1    |
| 1    24     6     | 3    29  8   | 2459   7     2459 |
| 3    7      249   | 5    6   1   | 8      29    249  |
+-------------------+--------------+-------------------+


Notice "X-Wing"
r4c79 and r8c79 contain the only 5's on those two rows.
Hence, 5 MUST be in one of those 4 cells in columns 7 and 9
- Remove 5 from candidate list of other cells in those columns.

That leaves only 4 in r2c9. Solve that and continue with singles to solve.

Mac

[Cec]

Hi leslyons,

If you need more help understanding the "code" tags, you could click on the "quote" button at the right hand corner of QBasicMac's above post to see where these two tags are inserted. Make sure only the last "code" tag has the 'forward slash' / as shown. Select the "Preview" button to view your work before posting it. Good luck
Cec

[tso]

For information on using CODE and other formatting options, click on the BBCODE link on the posting page.

http://forum.enjoysudoku.com/faq.php?mode=bbcode#5