The New Sudoku Players' Forum

[SteveG48]

Here's an easy one just to celebrate Friday:

Code: Select all

 *-----------*
 |...|...|...|
 |.3.|95.|..8|
 |..7|..6|.4.|
 |---+---+---|
 |..5|1..|9..|
 |.68|...|42.|
 |..2|..9|7..|
 |---+---+---|
 |.9.|2..|86.|
 |6..|.31|.9.|
 |...|...|...|
 *-----------*


[Cenoman]

TGIF

Code: Select all

 +------------------+------------------+-----------------+
 |  8     24   9    |  37   1   b34+7  |  6    5   c27   |
 |  24    3    6    |  9    5    47    |  12   17   8    |
 |  1     5    7    |  8    2    6     |  3    4    9    |
 +------------------+------------------+-----------------+
 |  47    47   5    |  1    8    2     |  9    3    6    |
 |  9     6    8    |  35   7    35    |  4    2    1    |
 |  3     1    2    |  4    6    9     |  7    8    5    |
 +------------------+------------------+-----------------+
 |  57    9    1    |  2    4    57    |  8    6    3    |
 |  6     8    4    |  57   3    1     |  25   9   d27   |
 | a25+7  27   3    |  6    9    8     |  15   1-7  4    |
 +------------------+------------------+-----------------+

BUG+2
(7)r9c1 == r1c6 - r1c9 = r8c9 => -7 r9c8; ste

[rjamil]

Easy one, ok, but, solved in two steps:

Code: Select all

 +------------+------------+------------+
 | 8    24  9 | 3+7 1  34-7| 6   5   2+7|
 | 24   3   6 | 9   5  47  | 12  17  8  |
 | 1    5   7 | 8   2  6   | 3   4   9  |
 +------------+------------+------------+
 | 47   47  5 | 1   8  2   | 9   3   6  |
 | 9    6   8 | 35  7  35  | 4   2   1  |
 | 3    1   2 | 4   6  9   | 7   8   5  |
 +------------+------------+------------+
 | 57   9   1 | 2   4  57  | 8   6   3  |
 | 6    8   4 | 5+7 3  1   | 25  9   2+7|
 | 257  27  3 | 6   9  8   | 15  17  4  |
 +------------+------------+------------+

1) X-Wing: Column wise 7 @ r18c49 => -7 @r1c6; and

Code: Select all

 +------------+-----------+------------+
 | 8    24  9 | 37  1  34 | 6   5   27 |
 | 2+4  3   6 | 9   5 *47 | 12  17  8  |
 | 1    5   7 | 8   2  6  | 3   4   9  |
 +------------+-----------+------------+
 |*47   47  5 | 1   8  2  | 9   3   6  |
 | 9    6   8 | 35  7  35 | 4   2   1  |
 | 3    1   2 | 4   6  9  | 7   8   5  |
 +------------+-----------+------------+
 | 5-7  9   1 | 2   4  5+7| 8   6   3  |
 | 6    8   4 | 57  3  1  | 25  9   27 |
 | 257  27  3 | 6   9  8  | 15  17  4  |
 +------------+-----------+------------+

2) M-Wing: 47 @ r2c6 47 @ r4c1 SL 4 @ r2c16 SL 7 @ r27c6 => -7 @ r7c1; stte

R. Jamil

[Ngisa]

Code: Select all

+----------------+----------------+----------------+
| 8      24    9 | 37    1    347 | 6     5     27 |
|c24     3     6 | 9     5    47  |c12   c17    8  |
| 1      5     7 | 8     2    6   | 3     4     9  |
+----------------+----------------+----------------+
| 47     47    5 | 1     8    2   | 9     3     6  |
| 9      6     8 | 35    7    35  | 4     2     1  |
| 3      1     2 | 4     6    9   | 7     8     5  |
+----------------+----------------+----------------+
| 57     9     1 | 2     4    57  | 8     6     3  |
| 6      8     4 | 57    3    1   | 25    9     27 |
|b257   a27    3 | 6     9    8   | 15    1-7   4  |
+----------------+----------------+----------------+


(7=2)r9c2 - r9c1 = (217)r2c178 => - 7r9c8; stte
Thanks Steve for giving us time to celebrate

Clement

[RSW]

Code: Select all

 +------------+----------+-----------+
 | 8   *4-2 9 | 37 1 347 | 6   5 d27 |
 | 24   3   6 | 9  5 47  | 12 c17 8  |
 | 1    5   7 | 8  2 6   | 3   4  9  |
 +------------+----------+-----------+
 | 47   47  5 | 1  8 2   | 9   3  6  |
 | 9    6   8 | 35 7 35  | 4   2  1  |
 | 3    1   2 | 4  6 9   | 7   8  5  |
 +------------+----------+-----------+
 | 57   9   1 | 2  4 57  | 8   6  3  |
 | 6    8   4 | 57 3 1   | 25  9  27 |
 | 257 a27  3 | 6  9 8   | 15 b17 4  |
 +------------+----------+-----------+


(2=7)r9c2 - (7)r9c8 = (7)r2c8 - (7=2)r1c9 => -2r1c2; stte

Thanks for the puzzle!

[jco]

Thanks Steve for giving us time to celebrate
Clement

Ditto!

After basics

Code: Select all

.--------------------------------------------------.
| 8    24   9    | 37   1    347  | 6    5    27   |
|d24   3    6    | 9    5   e4-7  | 12   17   8    |
| 1    5    7    | 8    2    6    | 3    4    9    |
|----------------+----------------+----------------|
|c47   47   5    | 1    8    2    | 9    3    6    |
| 9    6    8    | 35   7    35   | 4    2    1    |
| 3    1    2    | 4    6    9    | 7    8    5    |
|----------------+----------------+----------------|
|b57   9    1    | 2    4   a57   | 8    6    3    |
| 6    8    4    | 57   3    1    | 25   9    27   |
| 257  27   3    | 6    9    8    | 15   17   4    |
'--------------------------------------------------'

S-Wing (7)r7c6 = (7)r7c1 - (7=4)r4c1 - (4)r2c1 = (4)r2c6 => -7 r2c6; ste

[Leren]

Code: Select all

*---------------------------------*
| 8   24 9 | 37 1 347 | 6   5  27 |
|a24  3  6 | 9  5 47  |d1-2 17 8  |
| 1   5  7 | 8  2 6   | 3   4  9  |
|----------+----------+-----------|
| 47  47 5 | 1  8 2   | 9   3  6  |
| 9   6  8 | 35 7 35  | 4   2  1  |
| 3   1  2 | 4  6 9   | 7   8  5  |
|----------+----------+-----------|
| 57  9  1 | 2  4 57  | 8   6  3  |
| 6   8  4 | 57 3 1   | 25  9  27 |
|b257 27 3 | 6  9 8   |c15  17 4  |
*---------------------------------*

L3 Wing: (2) r2c1 = (2-5) r9c1 = (5-1) r9c7 = (1) r2c7 => - 2 r2c7; stte

Leren

[SteveG48]

Happy Saturday, and thanks to all for the solutions.

My own pen and paper solution was the x-wing followed by BUG+1. After that, my one-stepper was the same as Cenoman's.

All of the Stumble series are puzzles that I come across in my daily reading- usually in the local newspaper. If a puzzle seems to be a cut above the average newspaper puzzle, I may post it here.

Unfortunately, I typically only come across 1 or 2 suitable puzzles per month. This one barely made the cut.

I like the fact that folks are posting and discussing puzzles in the non-one-step category, but I think that there is still interest in the one-step game. Accordingly, I think I'll try something different in addition to the Stumble series. Occasionally I'll work a Hodoku generated puzzle in the unfair category that strikes me as interesting. I'm going to try posting a few of these. I will not be vetting them to see if they have one-step solutions, though they may have. Multi-step solutions are also welcome. If people seem to be interested, I'll continue as time allows. If not, it's nothing ventured nothing gained.

[rjamil]

Another M-Wing OTP solution (similar cells used as RSW but different elimination cell):

Code: Select all

 +------------+------------+------------+
 | 8    4+2 9 | 37  1  347 | 6   5  *27 |
 | 24   3   6 | 9   5  47  | 12  1+7 8  |
 | 1    5   7 | 8   2  6   | 3   4   9  |
 +------------+------------+------------+
 | 47   47  5 | 1   8  2   | 9   3   6  |
 | 9    6   8 | 35  7  35  | 4   2   1  |
 | 3    1   2 | 4   6  9   | 7   8   5  |
 +------------+------------+------------+
 | 57   9   1 | 2   4  57  | 8   6   3  |
 | 6    8   4 | 57  3  1   | 25  9   27 |
 | 257 *27  3 | 6   9  8   | 15  1-7 4  |
 +------------+------------+------------+

M-Wing: 27 @ r1c9 27 @ r9c2 SL 2 @ r1c29 SL 7 @ r1c9 r2c8 => -7 @ r9c8; stte

NB:

My own pen and paper solution was the x-wing followed by BUG+1.

Surprisingly, yzfwsf's software YZF_Sudoku won't search BUG+1 after x-wing move.

R. Jamil

[yzfwsf]

Surprisingly, yzfwsf's software YZF_Sudoku won't search BUG+1 after x-wing move.

Code: Select all

Bivalue Universal Grave + 1:  => r9c1 = 7;stte

[denis_berthier]

.

Code: Select all

Resolution state after Singles and whips[1]:
   +-------------+-------------+-------------+
   ! 8   24  9   ! 37  1   347 ! 6   5   27  !
   ! 24  3   6   ! 9   5   47  ! 12  17  8   !
   ! 1   5   7   ! 8   2   6   ! 3   4   9   !
   +-------------+-------------+-------------+
   ! 47  47  5   ! 1   8   2   ! 9   3   6   !
   ! 9   6   8   ! 35  7   35  ! 4   2   1   !
   ! 3   1   2   ! 4   6   9   ! 7   8   5   !
   +-------------+-------------+-------------+
   ! 57  9   1   ! 2   4   57  ! 8   6   3   !
   ! 6   8   4   ! 57  3   1   ! 25  9   27  !
   ! 257 27  3   ! 6   9   8   ! 15  17  4   !
   +-------------+-------------+-------------+
44 candidates

Code: Select all

x-wing-in-columns: n7{c4 c9}{r1 r8} ==> r1c6≠7
biv-chain[3]: r1c9{n2 n7} - b9n7{r8c9 r9c8} - r9c2{n7 n2} ==> r1c2≠2
stte

SudoRules finds the bug+1 (if the rule is activated):

Code: Select all

x-wing-in-columns: n7{c4 c9}{r1 r8} ==> r1c6≠7
************ BEWARE: ASSUMPTION OF UNIQUENESS USED ******************
bug+1 for number n7 in cell r9c1 ==> r9c1=7
stte

[rjamil]

Hi yzfwsf,

Code: Select all

Bivalue Universal Grave + 1:  => r9c1 = 7;stte

I have a copy of YZF_Sudoku 2.0.0.625.

Screenshot link attached for above mentioned puzzle's Tool / Find all steps - state after X-Wing move for your kind information:

R. Jamil

[yzfwsf]

Hi yzfwsf,

Code: Select all

Bivalue Universal Grave + 1:  => r9c1 = 7;stte

I have a copy of YZF_Sudoku 2.0.0.625.

Screenshot link attached for above mentioned puzzle's Tool / Find all steps - state after X-Wing move for your kind information:

R. Jamil

Hi:
The various techniques in my solver are user configurable, you can enable or disable a technique, and you can adjust the order in which the techniques are invoked.
These configurations are set in Edit->Preferences->Techniques.

[rjamil]

Hi:
The various techniques in my solver are user configurable, you can enable or disable a technique, and you can adjust the order in which the techniques are invoked.
These configurations are set in Edit->Preferences->Techniques.

Great! I never used such option before.
Showed after enabling BUGOne move.

Many thanks.

R. Jamil