The New Sudoku Players' Forum

[storm_norm]

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. . 1 . . . 2 . .
 . 3 . 2 . 4 . 5 .
 6 . . . . . . . 4
 . 6 . 7 . 3 . 8 .
 . . . . . . . . .
 . 8 . 1 . 2 . 3 .
 9 . . . . . . . 5
 . 1 . 3 . 5 . 2 .
 . . 7 . . . 8 . .  m_b_metcalf

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.------------------------.------------------------.------------------------.
| 4578    479     1      | 5689    356789  6789   | 2       679     36789  |
| 78      3       89     | 2       16789   4      | 1679    5       16789  |
| 6       279     2589   | 589     135789  1789   | 1379    179     4      |
:------------------------+------------------------+------------------------:
| 12      6       2459   | 7       459     3      | 1459    8       129    |
| 123     2479    23459  | 45689   45689   689    | 145679  14679   12679  |
| 457     8       459    | 1       4569    2      | 45679   3       679    |
:------------------------+------------------------+------------------------:
| 9       24      23468  | 468     124678  1678   | 13467   1467    5      |
| 48      1       468    | 3       46789   5      | 4679    2       679    |
| 23      5       7      | 469     12469   169    | 8       1469    1369   |
'------------------------'------------------------'------------------------'

this was solved using a sudecoq. ingoring it, this is my route. and its not pretty.

1.jellyfish on 9: r1359c3579 <> 9

2. (8)r1c9 = (8)r2c9 - (8=7)r2c1 - (7)r6c1 = (7-9)r5c2 = (9)r46c3 - (9=8)r2c3; r1c1 <> 8

3. (7=8)r2c1 - (4=8)r8c1 - (4=2)r7c2 - (2)r3c2 = (2-5)r3c3 = (5)r1c1; r1c1 <> 7

4. (8)r3c3 = (8)r2c13 - (8)r2c9 = (8-3)r1c9 = (3)r9c9 - (3)r9c1 = (3)r7c3; r7c3 <> 8

5. loop...(3)r9c1 = (3-6)r7c3 = (6-8)r8c3 = (8)r8c1 - (8=7) r2c1 - (7)r6c1 = (7-9)r5c2 = (9)r46c3 - (9=8)r2c3 - (8)r2c9 = (8-3)r1c9 = (3)r9c9; means that r7c3 <> 2,4... r8c3 <> 4... r5c2 <> 2,4... r2c9 <> 7,6

6. (3=6)r7c3 - (6=8)r8c3 - (8)r8c1 = (8)r2c1 - (8)r2c9 = (8-3)r1c9 = (3)r9c9; r9c1 <> 3

7. X-wing on 4; r59c357 <> 4

8. (9=8)r3c4 - (8=6)r7c4 - (6=1)r9c5 - (1)r23c5 = (1)r3c6; r3c6 <> 9

9. (9=8)r3c4 - (8)r7c4 = (8-7)r7c6 = (7-4)r8c5 = (4)r9c4; r9c4 <> 9

10. (6=7)r1c6 - (7)r3c5 = (7-9)r8c5 = (9)r9c6; r9c6 <> 6

11. ER on 6; R7c6 <> 6

12. (7=6)r1c8 - (6)r79c8 = (6-7)r7c7 = (7)r7c6; r1c6 <> 7

13. xy-chain (6=8)r7c4 - (8=9)r3c4 - (1=9)r2c5 - (1=6)r9c5; r9c4 <> 6

14. loop... (9=1)r3c8 - (1)r79c8 = (1-7) = (7-8)r7c6 = (8)r7c4 - (8=9)r3c4; means r7c6 <> 1

15. xy-wing... {789} r9c6 <> 9

I welcome all insight.

[daj95376]

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 after Naked Quad and Jellyfish -- and skipping continuous nice loops
 +--------------------------------------------------------------------------------+
 |  4578    479     1       |  5689    35678   6789    |  2       679     3678    |
 |  78      3       89      |  2       16789   4       |  1679    5       16789   |
 |  6       279     258     |  589     13578   1789    |  137     179     4       |
 |--------------------------+--------------------------+--------------------------|
 |  12      6       2459    |  7       459     3       |  1459    8       129     |
 |  123     2479    2345    |  45689   4568    689     |  14567   14679   1267    |
 |  457     8       459     |  1       4569    2       |  45679   3       679     |
 |--------------------------+--------------------------+--------------------------|
 |  9       24      23468   |  468     124678  1678    |  13467   1467    5       |
 |  48      1       468     |  3       46789   5       |  4679    2       679     |
 |  23      5       7       |  469     1246    169     |  8       1469    136     |
 +--------------------------------------------------------------------------------+


A) Notice [r2c13]=789 and [r2c2]=3
B) Eliminate common candidate and set [r2c1]=7 & [r2c3]=9
C) Notice an immediate contradiction in [c2]

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 *-----------------------------------------------------------------------------*
 | 458     4       1       | 5689    35678   6789    | 2       679     3678    |
 | 7       3       9       | 2       168     4       | 16      5       168     |
 | 6       2       258     | 589     13578   1789    | 137     179     4       |
 |-------------------------+-------------------------+-------------------------|
 | 12      6       245     | 7       459     3       | 1459    8       129     |
 | 123     24+79   2345    | 45689   4568    689     | 14567   14679   1267    |
 | 45      8       45      | 1       4569    2       | 45679   3       679     |
 |-------------------------+-------------------------+-------------------------|
 | 9       24      23468   | 468     124678  1678    | 13467   1467    5       |
 | 48      1       468     | 3       46789   5       | 4679    2       679     |
 | 23      5       7       | 469     1246    169     | 8       1469    136     |
 *-----------------------------------------------------------------------------*


D) One of [r2c1]=8 or [r2c3]=8 must be true. Leading to the following eliminations in (8).

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 eliminations in (8)
 +--------------------------------------------------------------------------------+
 |  457-8   479     1       |  5689    35678   6789    |  2       679     3678    |
 |  78      3       89      |  2       1679-8  4       |  1679    5       1679-8  |
 |  6       279     25-8    |  589     13578   1789    |  137     179     4       |
 |--------------------------+--------------------------+--------------------------|
 |  12      6       2459    |  7       459     3       |  1459    8       129     |
 |  123     2479    2345    |  45689   4568    689     |  14567   14679   1267    |
 |  457     8       459     |  1       4569    2       |  45679   3       679     |
 |--------------------------+--------------------------+--------------------------|
 |  9       24      23468   |  468     124678  1678    |  13467   1467    5       |
 |  48      1       468     |  3       46789   5       |  4679    2       679     |
 |  23      5       7       |  469     1246    169     |  8       1469    136     |
 +--------------------------------------------------------------------------------+


E) SSTS reduces puzzle to:

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 *-----------------------------------------------------------*
 | 4     9     1     | 5     3     67    | 2     67    8     |
 | 7     3     8     | 2     169   4     | 169   5     169   |
 | 6     2     5     | 89    178   1789  | 3     179   4     |
 |-------------------+-------------------+-------------------|
 | 1     6     49    | 7     459   3     | 459   8     2     |
 | 3     7     2     | 4689  568   689   | 156   1469  16    |
 | 5     8     49    | 1     469   2     | 4679  3     679   |
 |-------------------+-------------------+-------------------|
 | 9     4     3     | 68    2     1678  | 167   16    5     |
 | 8     1     6     | 3     479   5     | 479   2     79    |
 | 2     5     7     | 469   16    169   | 8     1469  3     |
 *-----------------------------------------------------------*


F) I'll let others worry about completing the solution from here.

===== ===== =====

Although I don't understand Sue de Coq, I've run enough SdC puzzles through my solver to notice that they often have common eliminations with a short continuous loop constrained to two boxes. I further observed this taletell pattern in many of the continuous loops.

[hobiwan]

A bit shorter (but still pretty ugly):

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Jellyfish: 9 r2468 c3579 => r1c59,r3c357,r5c3579,r9c59<>9

.--------------------------.---------------------.----------------------.
|  45-7-8  *479      1     | 5689   35678   6789 | 2      679    3678   |
| *78       3       *89    | 2      167-89  4    | 1679   5      167-89 |
|  6       *279      25-8  | 589    13578   1789 | 137    179    4      |
:--------------------------+---------------------+----------------------:
|  12       6        2459  | 7      459     3    | 1459   8      129    |
|  123     *-2-479   2345  | 45689  4568    689  | 14567  14679  1267   |
| *457      8        459   | 1      4569    2    | 45679  3      679    |
:--------------------------+---------------------+----------------------:
|  9        24       23468 | 468    124678  1678 | 13467  1467   5      |
|  48       1        468   | 3      46789   5    | 4679   2      679    |
|  23       5        7     | 469    1246    169  | 8      1469   136    |
'--------------------------'---------------------'----------------------'
Loop r5c2 =7= r6c1 -7- r2c1 -8- r2c3 -9- r13c2 =9= r5c2 => r5c2<>24, r1c1<>78, r2c59,r3c3<>8
Singles
Locked Candidates Type 1 (Pointing): 7 in b3 => r7c8<>7

.-----------.-------------------.-------------------.
| 4  9  1   | 5     3     *67   |  2     *-67   8   |
| 7  3  8   | 2     169    4    |  169    5     169 |
| 6  2  5   | 89    178    1789 |  3      179   4   |
:-----------+-------------------+-------------------:
| 1  6  249 | 7     459    3    |  459    8     29  |
| 3  7  24  | 4689  4568   689  |  1456   1469  126 |
| 5  8  49  | 1     469    2    |  4679   3     679 |
:-----------+-------------------+-------------------:
| 9  4  3   | 68    2     *1678 | *167   *16    5   |
| 8  1  6   | 3     479    5    |  479    2     79  |
| 2  5  7   | 469   146    169  |  8     *1469  3   |
'-----------'-------------------'-------------------'
Loop r1c8 -6- r79c8 =6= r7c7 =7= r7c6 -7- r1c6 =7= r1c8 => r1c8<>6
Singles
X-Wing: 4 c48 r59 => r5c357,r9c5<>4

.-----------.--------------------.-----------------.
| 4  9  1   |  5      3     6    | 2     7     8   |
| 7  3  8   |  2     *19    4    | 169   5     169 |
| 6  2  5   | *89    *178  -1789 | 3     19    4   |
:-----------+--------------------+-----------------:
| 1  6  249 |  7      459   3    | 459   8     29  |
| 3  7  2   |  4689  *568  *89   | 156   1469  126 |
| 5  8  49  |  1      469   2    | 4679  3     679 |
:-----------+--------------------+-----------------:
| 9  4  3   |  68     2     178  | 167   16    5   |
| 8  1  6   |  3      479   5    | 479   2     79  |
| 2  5  7   |  469   -16   *19   | 8     1469  3   |
'-----------'--------------------'-----------------'
AIC r9c6 -9- r5c6 -8- r5c5 =8= r3c5 -8- r3c4 -9- r2c5 => r3c6,r9c5<>1
Singles

[storm_norm]

AIC r9c6 -9- r5c6 -8- r5c5 =8= r3c5 -8- r3c4 -9- r2c5 => r3c6,r9c5<>1
Singles

May I know how that chain would look in Eureka! ?

[Glyn]

storm_norm Here is the final chain in Eureka notation

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(1=9)r9c6-(9=8)r5c6-(8)r5c5=(8)r3c5-(8=9)r3c4-(9=1)r2c5 => r3c6,r9c5<>1

[storm_norm]

thank you, Glyn.

the NL notation can start with a weak inference so just making sure the Eureka notation wasn't. since it was pointed out to me that proper AIC's would start and end on strong inferences.

[Luke]

Storm, mind if I take a stab at the Sue de Coq we're ignoring?

Code: Select all

.------------------------.------------------------.------------------------.
| 45-78  C479     1      | 5689    356789  6789   | 2       679     36789  |
|a78      3      a89     | 2       16789   4      | 1679    5       16789  |
| 6      C279     258-9  | 589     135789  1789   | 1379    179     4      |
:------------------------+------------------------+------------------------:
| 12      6       2459   | 7       459     3      | 1459    8       129    |
| 123    -2-479   23459  | 45689   45689   689    | 145679  14679   12679  |
| 457     8       459    | 1       4569    2      | 45679   3       679    |
:------------------------+------------------------+------------------------:
| 9      b24      23468  | 468     124678  1678   | 13467   1467    5      |
| 48      1       468    | 3       46789   5      | 4679    2       679    |
| 23      5       7      | 469     12469   169    | 8       1469    1369   |
'------------------------'------------------------'------------------------'

Sets: Core = C = [r13c2] = [2479]; a = [r2c13] = [789]; b = [r7c2] = [24].
Core and set a share values 7 and 9.
Core and set b share values 2 and 4.
Sets a and b do not share any Core values with one another.

Eliminations: Any 7,9 in box 1 not in Core or set a; any 2,4 in c2 not in Core or set b.

Either I've got this wrong or there's another SdC, because it leads nowhere.

[Glyn]

A pretty good stab Luke451 just add the elimination of some 8's and you've got it. Though perhaps someone will point out that they can't formally be included.
The full set is r1c1<>7;r1c1,r3c3<>8;r3c3<>9;r5c2<>2,4.
My reasoning is that based on the trigger cell r7c2 the group of 4 cells [r1c2,r2c13,r3c2] contains either {2789}|{4789} thus locking {789}.
BTW 300 posts does that mean 3 cakes

[Luke]

<Lighting candles.....>
<Singing, toasting....>

Of course you're right about the 8's, [789] are indeed locked.

[storm_norm]

there was a nother puzzle that mauricio posted in the patterns game that also had a su de coq in the beginning stages of the puzzle and I used a AIC loop to make the same eliminations.

that said... is there an AIC that does the same eliminations as the Su de coq in the puzzle above? and i am guessing it would have to be a loop.

[daj95376]

AIC r9c6 -9- r5c6 -8- r5c5 =8= r3c5 -8- r3c4 -9- r2c5 => r3c6,r9c5<>1
Singles

May I know how that chain would look in Eureka! ?

In NL notation, I believe this AIC chain should read:

Code: Select all

1- r9c6 -9- r5c6 -8- r5c5 =8= r3c5 -8- r3c4 -9- r2c5 -1 => r3c6,r9c5<>1


[daj95376]

The full set is r1c1<>7;r1c1,r3c3<>8;r3c3<>9;r5c2<>2,4.

It doesn't include 8s in [r2]

Code: Select all

 [r5c2]=7=[r6c1]-7-[r2c1]-8-[r2c3]-9-[r46c3]=9=[r5c2]   continuous loop
 +--------------------------------------------------------------------------------+
 |  45-78   479     1       |  5689    35678   6789    |  2       679     3678    |
 |  78      3       89      |  2       1679-8  4       |  1679    5       1679-8  |
 |  6       279     25-8    |  589     13578   1789    |  137     179     4       |
 |--------------------------+--------------------------+--------------------------|
 |  12      6       2459    |  7       459     3       |  1459    8       129     |
 |  123     79-24   2345    |  45689   4568    689     |  14567   14679   1267    |
 |  457     8       459     |  1       4569    2       |  45679   3       679     |
 |--------------------------+--------------------------+--------------------------|
 |  9       24      23468   |  468     124678  1678    |  13467   1467    5       |
 |  48      1       468     |  3       46789   5       |  4679    2       679     |
 |  23      5       7       |  469     1246    169     |  8       1469    136     |
 +--------------------------------------------------------------------------------+


One of [r2c1]=8 or [r2c3]=8 must be true.

A forcing net based on ...

Code: Select all

Stream #1: [r2c1]=8
Stream #2: [r2c3]=8


... will result in the same eliminations as the continuous loop. See, I wasn't wasting your time with my hokey approach earlier in the thread.

[Glyn]

daj95376 That's interesting. So many ways of viewing the Structure with different degrees of success

The AIC I used was

Code: Select all

(4789=2)r13c2,r2c13-(2=4)r7c2-(4=2789)13c2,r2c13

to give alternative quads to get the eliminations of 789 in box 1. However if we were to accept this closed a loop with a 4-cell node then the 2's and 4's would be accounted for as well. This won't give r2c59<>8 until the obvious next move.

Your's and Hobiwan's loops include the alignment of the 8's in r2c13 so they catch them straight away.

[daj95376]

While we're talking about alternate ways to view the structure, take a look at the grouped strong links on (7) and (9) in [c2].

Code: Select all

 [r13c2]=7=[r5c2]
 [r13c2]=9=[r5c2]


Which can be combined into:

Code: Select all

 [r13c2]=7=[r5c2]=9=[r13c2]


Anything that eliminates (7) and (9) in [r13c2] will force both of them to be true in [r5c2] -- a contradiction. Thus, [r2c1]=7 and [r2c3]=9 would result in a contradiction. This supports my assertion that [r2c1]=8 or [r2c3]=8 must be true.

Anything that eliminates (7) and (9) in [r5c2] will force one of them to be true in [r1c2] and the other to be true in [r3c2]. However, we then get [r2c1]=8 and [r2c3]=8 -- a contradiction. Thus, setting [r5c2]=2|4 would result in a contradiction.

Norm: My apologies for helping send your original post off on a tangent

[Glyn]

storm_norm Hope our interventions have been ok. Those loops replicate the Sue de Coq (on speed )

daj95376 your loop did it all anyway the weak inference on 8 between r2c1 and r2c3 kills those 8's in Row 2 automatically.