The New Sudoku Players' Forum

[Cec]

The following puzzle appeared in today's Melbourne "Herald-Sun" rated Hard: (Sorry about row 1 not lining up. I can't understand why this happens only on this row as the "template" grid I've prepared in Word is correct - any tip to correct this would be appreciated)

Code: Select all

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


After basic elimination techniques I got as far as this:
*-----------------------------------------------------------------------------*
| 6 148 14 | 5 1489 7 | 19 3 2 |
| 248 7 3 | 1289 12489 1489 159 6 15 |
| 9 12 5 | 12 3 6 | 4 7 8 |
|-------------------------+-------------------------+-------------------------|
| 458 9 67 | 3 158 2 | 1568 1458 1567 |
| 1 458 2 | 7 6 58 | 3 458 9 |
| 58 3 67 | 4 1589 1589 | 12568 1258 1567 |
|-------------------------+-------------------------+-------------------------|
| 3 6 8 | 129 1259 159 | 7 1259 4 |
| 245 1245 149 | 1289 7 3 | 12568 12589 156 |
| 7 125 19 | 6 124589 14589 | 1258 12589 3 |
*-----------------------------------------------------------------------------*
In the Simple Sudoku program, the "colours" technique enables candidate 2 to be excluded from r8c4 after which the program shows "no hint available" when the "hint" button is selected.

As all puzzles in this paper are stated to be from Pappocom I can't understand why additional hints are not given to show how to solve this puzzle. Any advice as to the techniques necessary to solve this puzzle would be appreciated.
Cec

[angusj]

In the Simple Sudoku program ... after which the program shows "no hint available" when the "hint" button is selected.

Hi Cec. I just copy and pasted it into Simple Sudoku and it solved it without having to resort to anything 'fancy'. I wonder if you made a mistake with what you loaded into SS?

[Animator]

That's what happens if you ignore a clue...

The top grid: r8c2 = 5,
The bottom grid: r8c2 = 1245


Update: this is what happens when you ignore two clues...

Top grid: r6c6 = 1,
Bottom grid: r6c6 = 1589

Update2: You are ignoring 5 clues.. Do you really expect to find a solution if you leave out 5 numbers?

Top grid: r7c5 = 1
Bottom grid: r7c5 = 1259

Top grid: r9c6 = 4
Bottom grid: r9c6 = 14589

Top grid: r8c8 = 1
Bottom grid: r8c8 = 12589

[Cec]

"... I wonder if you made a mistake with what you loaded into SS?"

Thanks angusj for your prompt reply and you were right - I made a mistake in loading this puzzle into SS. I'm trying to come up with an "excuse" to explain how this occurred but I can't I usually double check to make sure but ... ah! still no excuse !
Cec

[Cec]

"Do you really expect to find a solution if you leave out 5 numbers?.."

Thanks Animator. I'm trying to think how to explain this embarrassing mistake on my part but I can't. - Sorry to put you through this but imagine how I feel?
Cec