The New Sudoku Players' Forum

[Jeans]

This was supposed to be a Difficult one (although was on a Friday so maybe it was a misprint?) but am still struggling with it. Can anyone help me please - at least one clue to get me on my way . .

45-|---|-3 -
-7-|96-|--5
-92|35-|---
-------------
98-|7--|-6-
-1-|---|-8-
-3-|--9|-71
--------------
-2-|47-|8--
14-|-23| ---
-6-|-9-|--4

In anticipation . . . .

[re'born]

Jeans,

If you post your candidate grid, then it will help people to know how far into the puzzle you have reached. With that being said, I will tell you that the puzzle can be solved with several applications of locked candidates and 1 naked pair, the rest being singles. If you show us where you are, we can give more precise help.

[tarek]

Look at the intersection cells of row 8 & Box 9.........

Look for a naked double (the same naked double for both sectors)....................


you can apply it in either row 8 or box 9 to solve the puzzle...


tarek

[QBasicMac]

Still not there yet?

Locked candidate 4 in box 2
Translation: Cells r2c6 and r3c6 have the only 4's in that box. Thus 4's can be eliminated from r4c6 and r5c6 since there can be only one 4 in column 6 and it has to fall in r23c6.

Locked candidate 4 in box 6. Adios 4's in r23c7.

Locked candidate 5 in box 6.

Locked candidate 9 in col 8.
This one is interesting. This time all 9's in column 8 fall in row 7 and row 8 (r78c8). That means the rest of the 9's in that box can be erased.

Naked pair 67 in row 8.
Translation: In row 8 there are two cells that have exactly candidates 6 and 7. So one must be 6 and the other 7. As a result, any other candidates 6 and 7 in row 8 can be erased.

Naked pair 67 in box 9.
Talking about the same pair here, but now noticing that they are in the same box. So the 6 in r7c9 and the 7 in r9c7.

Here are the resultant pencilmarks.

Code: Select all

+---------------+-----------------+-------------------+
| 4     5  168  | 128   18   1278 | 12679  3    26789 |
| 38    7  138  | 9     6    1248 | 12     124  5     |
| 68    9  2    | 3     5    1478 | 167    14   678   |
+---------------+-----------------+-------------------+
| 9     8  45   | 7     134  125  | 2345   6    23    |
| 2567  1  4567 | 256   34   256  | 23459  8    239   |
| 256   3  456  | 2568  48   9    | 245    7    1     |
+---------------+-----------------+-------------------+
| 35    2  359  | 4     7    156  | 8      159  {3}   |
| 1     4  589  | 58    2    3    | 67     59   67    |
| 3578  6  3578 | 158   9    158  | 123    125  4     |
+---------------+-----------------+-------------------+


Note the naked single in r7c9. All downhill now.

Mac

[Jeans]

All

Many thanks for the various suggestions. Tarek you clue was the one that finally solved it for me. (Note: ALthough I still think the puzzle deserved to be a Fiendish level rather than merely Difficult!).

Till the next time!

[Pat]

#700 - Difficult

Code: Select all

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

I still think the puzzle deserved to be a Fiendish level rather than merely Difficult!

yes, Jeans, you are entirely correct,
the Pappocom rating on this puzzle is Hard.

it does need a duo, as everyone mentioned.

every Pappocom Medium puzzle i have ever seen
could be solved by box-line interaction - without using a duo.

[Heuresement]

If I recall correctly, that puzzle was an unusual one for The Times. In The Times, Fiendish puzzles usually run on Wednesdays, Thursdays, Fridays and Saturdays, whereas on Monday and Tuesday, the puzzle is only ranked difficult. On that day, the Friday puzzle was only ranked as difficult. I remember completing it reasonably quickly, and then being disappointed to notice that it had only been ranked Difficult rather than Fiendish.

At that time, I never loaded it into the Pappcom program so thanks Pat for the clearing this one up for me. They must have made a mistake in the printing.