The New Sudoku Players' Forum

[stumble]

It’s time to admit that this sudocue.net 12-6-07Mean has defeated me. This genre I can do maybe 50% of the time, and this one looks solvable. But not by me.

Initial puzzle:

Code: Select all

.------------------------.------------------------.------------------------.
| 359     1259    2359   | 8       357     235679 | 2367    4       23     |
| 39      29      2349   | 23469   347     1      | 2367    8       5      |
| 6       7       23458  | 2345    345     235    | 1       9       23     |
:------------------------+------------------------+------------------------:
| 4       2589    235789 | 135     6       3578   | 23579   1257    1239   |
| 1       589     35789  | 345     2       3578   | 34579   57      6      |
| 357     25      23567  | 1345    9       357    | 23457   1257    8      |
:------------------------+------------------------+------------------------:
| 589     4       1      | 2569    58      25689  | 25689   3       7      |
| 2       6       589    | 7       1358    3589   | 4589    15      149    |
| 5789    3       5789   | 12569   158     4      | 25689   1256    129    |
'------------------------'------------------------'------------------------'


after obvious cancellations:

Code: Select all

.---------------------.---------------------.---------------------.
| 359    1      2359  | 8      37     69    | 67     4      23    |
| 39     29     4     | 69     37     1     | 67     8      5     |
| 6      7      8     | 25     4      25    | 1      9      23    |
:---------------------+---------------------+---------------------:
| 4      2589   23579 | 135    6      578   | 359    1257   19    |
| 1      589    3579  | 345    2      578   | 3459   57     6     |
| 357    25     6     | 1345   9      57    | 345    1257   8     |
:---------------------+---------------------+---------------------:
| 589    4      1     | 2569   58     2569  | 2589   3      7     |
| 2      6      59*   | 7      158    3     | 589    15*    4     |
| 5789   3      57-9  | 259    158    4     | 2589   6      19*   |
'---------------------'---------------------'---------------------'


I believe I see an XYchain
(9) r9c9 –r8c8 – r8c3 => r9c3<>9
which does me no good at all. Somebody please tell me what is probably obvious?

[wintder]

Start over. This is an easy puzzle.

[Cec]

Hi stumble,
OK, I only find puzzles easy provided I can "spot" the clues. To help you along the way your pencilmark grid is as follows...

Code: Select all

.---------------------.---------------------.---------------------.
| 359    1      2359  | 8      37     69    | 67     4      23    |
| 39     29     4     | 69     37     1     | 67     8      5     |
| 6      7      8     | 25     4      25    | 1      9      23    |
:---------------------+---------------------+---------------------:
| 4      2589   23579 | 135    6      578   | 359    1257   19    |
| 1      589    3579  | 345    2      578   | 3459   57     6     |
| 357    25     6     | 1345   9      57    | 345    1257   8     |
:---------------------+---------------------+---------------------:
| 589    4      1     | 2569   58     2569  | 2589   3      7     |
| 2      6      59    | 7      158    3     | 589    15     4     |
| 5789   3      57-9  | 259    158    4     | 2589   6      19    |
'---------------------'---------------------'---------------------'


Assuming you understand the basic techniques such as naked and hidden singles, pairs, triples, etc. you will see a naked pair [25] in row3 (box2).Therefore as these two candidates cannot appear in any of the other cells on row3 then candidate 2 can be excluded from cell r3c9 which leaves a naked single [3] to solve that cell. Then look at each row to spot a hidden single which should enable you to complete the puzzle with naked singles popping up everywhere.

As an added exercise, but not necessary to solve this puzzle, note the naked triples [578] and [158] in boxes 5 and 8 respectively which enables these candidates to be excluded from other cells in these same boxes.

Cec

[stumble]

Hi stumble,
OK, I only find puzzles easy provided I can "spot" the clues. To help you along the way your pencilmark grid is as follows...

Code: Select all

.---------------------.---------------------.---------------------.
| 359    1      2359  | 8      37     69    | 67     4      23    |
| 39     29     4     | 69     37     1     | 67     8      5     |
| 6      7      8     | 25     4      25    | 1      9      23    |
:---------------------+---------------------+---------------------:
| 4      2589   23579 | 135    6      578   | 359    1257   19    |
| 1      589    3579  | 345    2      578   | 3459   57     6     |
| 357    25     6     | 1345   9      57    | 345    1257   8     |
:---------------------+---------------------+---------------------:
| 589    4      1     | 2569   58     2569  | 2589   3      7     |
| 2      6      59    | 7      158    3     | 589    15     4     |
| 5789   3      57-9  | 259    158    4     | 2589   6      19    |
'---------------------'---------------------'---------------------'


Assuming you understand the basic techniques such as naked and hidden singles, pairs, triples, etc. you will see a naked pair [25] in row3 (box2).Therefore as these two candidates cannot appear in any of the other cells on row3 then candidate 2 can be excluded from cell r3c9 which leaves a naked single [3] to solve that cell. Then look at each row to spot a hidden single which should enable you to complete the puzzle with naked singles popping up everywhere.

As an added exercise, but not necessary to solve this puzzle, note the naked triples [578] and [158] in boxes 5 and 8 respectively which enables these candidates to be excluded from other cells in these same boxes.

Cec

Arghhh!!! I thought I got rid of them all. And after staring at it long enough I guess they just disappeared. Well, at least I'm getting better at posting and reading this stuff.