Stumped again by very hard puzzle

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Stumped again by very hard puzzle

Postby luvsudoku » Mon Jan 30, 2006 3:59 pm

Sorry to post again so soon, but it was a rainy Sunday and I decided to
challenge myself with a bunch of hard puzzles. I got stuck on this one:

Code: Select all
------------------------------
|         | 7       |         |
| 1     4 | 5     9 |         |
|    7  9 |       1 | 8       |
------------------------------
|       7 |         |    5    |
|         | 3     4 |    6    |
|         |    2    |       9 |
------------------------------
|         |       7 |         |
|       2 | 4       | 1       |
| 4     3 | 9  5    |         |
------------------------------

I got as far as
Code: Select all
------------------------------------------------------------------------------------
|    23568    23568      568|        7     3468     2368|       59    12349   123456|
|        1     2368        4|        5      368        9|      367      237     2367|
|     2356        7        9|       26      346        1|        8      234    23456|
------------------------------------------------------------------------------------
|     2368    23468        7|      168        9       68|       34        5      138|
|      589      589      158|        3        7        4|        2        6       18|
|      368     3468      168|      168        2        5|      347     1378        9|
------------------------------------------------------------------------------------
|     5689     5689      568|      268        1        7|       59    23489   234568|
|        7     5689        2|        4      368      368|        1       89      568|
|        4        1        3|        9        5      268|       67      278     2678|
------------------------------------------------------------------------------------


Pointers to the next move is appreciated!
luvsudoku
 
Posts: 10
Joined: 29 January 2006

Postby tarek » Mon Jan 30, 2006 4:05 pm

Hi there sudoku-loving luvsudoku,

Code: Select all
*--------------------------------------------------------------------------*
| 23568   23568   568    | 7       3468    2368   | 59      12349   123456 |
| 1       2368    4      | 5       368     9      | 367     237     2367   |
| 2356    7       9      | 26      346     1      | 8       234     23456  |
|------------------------+------------------------+------------------------|
| 2368    23468   7      | 168     9       68     | 34      5       138    |
| 589     589     158    | 3       7       4      | 2       6       18     |
| 368     3468    168    | 168     2       5      | 347     1378    9      |
|------------------------+------------------------+------------------------|
| 5689    5689    568    | 268     1       7      | 59      23489   234568 |
| 7       5689    2      | 4       368     368    | 1       89      568    |
| 4       1       3      | 9       5       268    | 67      278     2678   |
*--------------------------------------------------------------------------*

34 is a Hidden Double in Row 7

Tarek
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tarek
 
Posts: 2622
Joined: 05 January 2006

Thanks!

Postby luvsudoku » Mon Jan 30, 2006 7:16 pm

Looking at it now it just jumps out at me LOL ;-)

That made the rest flow quickly - thanks!
luvsudoku
 
Posts: 10
Joined: 29 January 2006

Re: Stumped again by very hard puzzle

Postby Cec » Tue Jan 31, 2006 7:22 am

luvsudoku wrote:Looking at it now it just jumps out at me LOL ;-)

Yes, it does always seem that way when it's pointed out:) . I thought it also worth pointing out the alternative "clue" to this puzzle appeared in the same row 7 being the naked quad of [5689] [5689] [568] [59] in columns 1237. After these candidates are eliminated from other cells in this row a naked single [2] fills cell r7c4 leaving the naked pair [34] in r7c8 and r7c9 as spotted by tarek. It seems a personal observation as to whether it's easier to spot a naked quad or a hidden pair!
Cec
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