The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |...|4.8|...|
 |...|6.9|...|
 |..1|.7.|5..|
 |---+---+---|
 |.7.|...|.6.|
 |..4|7.2|8..|
 |5..|...|..1|
 |---+---+---|
 |4..|...|..2|
 |..8|.9.|3..|
 |.5.|...|.9.|
 *-----------*


Play/Print this puzzle online

[Ngisa]

Code: Select all

+-------------------+----------------+------------------+
| 37     2      6   | 4     5     8  | 9     1     37   |
| 378    348    5   | 6     1     9  |h24    23    3478 |
| 89     489    1   | 2     7     3  | 5     8-4   6    |
+-------------------+----------------+------------------+
| 389    7     f239 | 5     48    1  |g24    6     34   |
| 6      1      4   | 7     3     2  | 8     5     9    |
| 5      38    e23  | 9     48    6  | 7     23    1    |
+-------------------+----------------+------------------+
| 4      39     379 | 38    6     5  | 1     78    2    |
| 2      6      8   | 1     9    b47 | 3    a47    5    |
| 1      5     d37  | 38    2    c47 | 6     9     478  |
+-------------------+----------------+------------------+


(4=7)r8c8 - r8c6 = r9c6 - (7=3)r9c3 - (3=2)r6c3 - r4c3 = (2-4)r4c7 = (4)r2c7 => - 4r3c8; stte

Clement

[SpAce]

Code: Select all

.--------------.-----------.------------.
| 37  2   6    | 4   5  8  | 9   1   37 |
| 78  34  5    | 6   1  9  | 24  23  78 |
| 89  49  1    | 2   7  3  | 5   48  6  |
:--------------+-----------+------------:
| 39  7   29+3 | 5   8  1  | 24  6   34 |
| 6   1   4    | 7   3  2  | 8   5   9  |
| 5   8   2-3  | 9   4  6  | 7   23  1  |
:--------------+-----------+------------:
| 4   39  79+3 | 38  6  5  | 1   78  2  |
| 2   6   8    | 1   9  47 | 3   47  5  |
| 1   5   7-3  | 38  2  47 | 6   9   48 |
'--------------'-----------'------------'

BUG+2: (3)r[4==7]c3 => -3 r69c3; stte

[Cenoman]

Hi Clement, here is the PM I get after basics. You seem to have missed NP(23)r6c38...

Code: Select all

 +------------------+-----------------+-----------------+
 |  37   2    6     |  4    5    8    |  9    1    37   |
 |  78   34   5     |  6    1    9    |  24   23   78   |
 |  89   49   1     |  2    7    3    |  5    48   6    |
 +------------------+-----------------+-----------------+
 |  39   7    239   |  5    8    1    |  24   6    34   |
 |  6    1    4     |  7    3    2    |  8    5    9    |
 |  5    8    23    |  9    4    6    |  7    23   1    |
 +------------------+-----------------+-----------------+
 |  4    39   739   |  38   6    5    |  1    78   2    |
 |  2    6    8     |  1    9    47   |  3    47   5    |
 |  1    5    37    |  38   2    47   |  6    9    48   |
 +------------------+-----------------+-----------------+

[SpAce]

Hi Clement, here is the PM I get after basics. You seem to have missed NP(23)r6c38...

Or three singles + one pointing pair + one hidden pair/naked triple. Then again, I guess there's no rule against not using all available basic steps before the kill? Clement's move is indeed stte with the PM he provided. (That being said, it's easier to compare solutions if they have the same pencil marks as the starting point).

[rjamil]

Code: Select all

...4.8......6.9.....1.7.5...7.....6...47.28..5.......14.......2..8.9.3...5.....9.
 +--------------+-------------+--------------+
 | 37   2   6   | 4     5  8  | 9   1   37   |
 | 78   34  5   | 6     1  9  | 24  23  78   |
 | 89   49  1   | 2     7  3  | 5   48  6    |
 +--------------+-------------+--------------+
 | 9+3  7   293 | 5     8  1  | 24  6   (34) |
 | 6    1   4   | 7     3  2  | 8   5   9    |
 | 5    8   2+3 | 9     4  6  | 7   23  1    |
 +--------------+-------------+--------------+
 | 4    39  379 | 38    6  5  | 1   78  2    |
 | 2    6   8   | 1     9  47 | 3   47  5    |
 | 1    5   7-3 | (38)  2  47 | 6   9   (48) |
 +--------------+-------------+--------------+

XY-Wing Transport: 348 @ r4c9 r9c49 Strong Link ERI 3 @ b4r4c3 => -3 @ r9c3; stte

R. Jamil

[SpAce]

Code: Select all

 +--------------+-------------+--------------+
 | 37   2   6   | 4     5  8  | 9   1   37   |
 | 78   34  5   | 6     1  9  | 24  23  78   |
 | 89   49  1   | 2     7  3  | 5   48  6    |
 +--------------+-------------+--------------+
 | 9+3  7   293 | 5     8  1  | 24  6   (34) |
 | 6    1   4   | 7     3  2  | 8   5   9    |
 | 5    8   2+3 | 9     4  6  | 7   23  1    |
 +--------------+-------------+--------------+
 | 4    39  379 | 38    6  5  | 1   78  2    |
 | 2    6   8   | 1     9  47 | 3   47  5    |
 | 1    5   7-3 | (38)  2  47 | 6   9   (48) |
 +--------------+-------------+--------------+

XY-Wing Transport: 348 @ r4c9 r9c49 Strong Link ERI 3 @ b4r4c3 => -3 @ r9c3; stte

Hi rjamil! That's a nice solution! However, using '+' in the grid for this purpose (apparently to indicate the ER corners?) is a bit confusing, as it's typically used to indicate the internal extra candidates of a deadly pattern. Thus, some other marker would probably be better for your purpose.

[rjamil]

Hi SpAce,

Hi rjamil! That's a nice solution!

Many thanks for the appreciation.

However, using '+' in the grid for this purpose (apparently to indicate the ER corners?) is a bit confusing, as it's typically used to indicate the internal extra candidates of a deadly pattern. Thus, some other marker would probably be better for your purpose.

I am yet to find something more appropriate to show ERI at the moment. Included box number with ERI cell coordinate but failed to represent the same into grid as well. Either just the ERI cell marker placement would be sufficient or whole ERI presentation need to be included for easy understanding.

R. Jamil

[SteveG48]

Code: Select all

 *--------------------------------------------------*
 | 37   2    6    | 4    5    8    | 9    1    37   |
 | 78   34   5    | 6    1    9    | 24   23   78   |
 |c89   4-9  1    | 2    7    3    | 5   b48   6    |
 *----------------+----------------+----------------|
 | 39   7    239  | 5    8    1    | 24   6    34   |
 | 6    1    4    | 7    3    2    | 8    5    9    |
 | 5    8    23   | 9    4    6    | 7    23   1    |
 *----------------+----------------+----------------|
 | 4   a39   379  |a38   6    5    | 1   a78   2    |
 | 2    6    8    | 1    9    47   | 3   b47   5    |
 | 1    5    37   | 38   2    47   | 6    9    48   |
 *--------------------------------------------------*


(9=378)r7c248 - (7=48)r38c8 - (8=9)r3c1 => -9 r3c2 ; stte

[SpAce]

I am yet to find something more appropriate to show ERI at the moment.

Well, I think you have plenty of options. The most widely used generic marker for various patterns is '*', I think. Or you could use brackets like you did with marking the XY-Wing (if you want, you can use [] or {} for the second pattern to differentiate it). Basically almost anything but '+' would work.

Either just the ERI cell marker placement would be sufficient

Please no, especially not with the '<>' as the marker (some people use it to mark givens). Marking only the ERI candidate is a bad idea also because few people would intuitively understand what it means. It's worse than marking just the corners (like you now have), but neither is optimal, I think.

or whole ERI presentation need to be included for easy understanding.

Yes, that would be my recommendation. It's easiest to understand for most people who probably think in terms of grouped links and not ERIs.

XY-Wing Transport: 348 @ r4c9 r9c49 Strong Link ERI 3 @ b4r4c3 => -3 @ r9c3; stte

Btw, what do you mean by the 'Strong Link' here? What is strongly linked to what?

[Ngisa]

Hi Clement, here is the PM I get after basics. You seem to have missed NP(23)r6c38...

Code: Select all

 

Yes, I missed it It is important to complete the basics, otherwise you can have an advantage of using candidates which were not supposed to be in that cell to make eliminations. Fortunately I did not use them in my chain in this puzzle.

[SpAce]

It is important to complete the basics, otherwise you can have an advantage of using candidates which were not supposed to be in that cell to make eliminations. Fortunately I did not use them in my chain in this puzzle.

How exactly could that ever be an advantage? I can't imagine any scenario where leaving free basic eliminations and even placements on the table would actually help anyone in these challenges. It can definitely make things more difficult but not easier. (Not really sure if you were joking or serious, though.)

[Ngisa]

It is important to complete the basics, otherwise you can have an advantage of using candidates which were not supposed to be in that cell to make eliminations. Fortunately I did not use them in my chain in this puzzle.

How exactly could that ever be an advantage? I can't imagine any scenario where leaving free basic eliminations and even placements on the table would actually help anyone in these challenges. It can definitely make things more difficult but not easier. (Not really sure if you were joking or serious, though.)

I agree with you, It makes things difficult most of the time. But, I do remember one time(not in this forum) one used an M-Wing to solve a puzzle by using candidates left accidentally in basic eliminations, when the candidates were removed the M-Wing was not there. I will try to find that puzzle if I can get it.

[rjamil]

Hi SpAce,

XY-Wing Transport: 348 @ r4c9 r9c49 Strong Link ERI 3 @ b4r4c3 => -3 @ r9c3; stte

Btw, what do you mean by the 'Strong Link' here? What is strongly linked to what?

It is based on Strong Link point 5.

As far as ERI presentation is concern, need more precise presentation to be thinking/suggesting.

R. Jamil

[SpAce]

I agree with you, It makes things difficult most of the time. But, I do remember one time(not in this forum) one used an M-Wing to solve a puzzle by using candidates left accidentally in basic eliminations, when the candidates were removed the M-Wing was not there. I will try to find that puzzle if I can get it.

Please do! It's quite possible that the M-Wing pattern was no longer there after the missed basic eliminations, but I'm pretty sure there was something else (probably simpler) with the same effect. I'll be happily surprised if I'm wrong.