The New Sudoku Players' Forum

by **storm_norm** » Wed Apr 09, 2008 6:26 am

Code: Select all: 3.7|..9|..6 ...|..7|... 82.|...|1.. ---+---+--- .5.|.6.|..1 ...|354|... 7..|.9.|.6. ---+---+--- ..5|...|.12 ...|9..|... 4..|2..|3.7

way over my head

enjoy,

Norm

by **eleven** » Wed Apr 09, 2008 1:53 pm

Code: Select all: *----------------------------------------------------------------* | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 *12348 7 | 2489 23489 3489 | | 8 2 469 | 456 *34 36 | 1 7 3459 | |---------------------+---------------------+--------------------| | 29 5 23489 | 7 6 28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 *348 2348 | 18 9 128 | 2458 6 3458 | |---------------------+---------------------+--------------------| | 69 #36789 5 | 468 #3478 368 | 4689 1 2 | | 126 #13678 12368 | 9 #13478 13568 | 4568 458 458 | | 4 1689 1689 | 2 18 1568 | 3 589 7 | *----------------------------------------------------------------*

UR 37, r6c2=3 or r23c5=3
r23c5=3 -> r3c6=6 -> r7c4=6
r6c2=3 -> r8c3=3 -> r8c1=2 -> r4c1=9 -> r7c1=6
I.e. r7c267<>6

Code: Select all: *--------------------------------------------------------------* | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | |--------------------+--------------------+--------------------| | 29 5 23489 | 7 6 28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 128 | 2458 6 3458 | |--------------------+--------------------+--------------------| |*69 3789 5 |*468 3478 38 |*489 1 2 | | 12 1378 1238 | 9 13478 1358 | 6 458 458 | | 4 1689 1689 | 2 18 *1568 | 3 *589 7 | *--------------------------------------------------------------*

Either r9c6=5 or (r9c8=5 -> r7c7=9 -> r7c1=6 -> r9c6=6), i.e. r9c6=56

Code: Select all: *--------------------------------------------------------------* | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | |--------------------+--------------------+--------------------| |-29 5 23489 | 7 6 *28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 *128 | 2458 6 3458 | |--------------------+--------------------+--------------------| | 69 3789 5 | 468 3478 38 | 489 1 2 | |*12 1378 1238 | 9 13478 *1358 | 6 458 458 | | 4 1689 1689 | 2 18 56 | 3 589 7 | *--------------------------------------------------------------*

Either r8c1=2 or (r8c1=1 -> r6c6=1 -> r3c6=2), i.e. r4c1<>2

by **daj95376** » Wed Apr 09, 2008 4:52 pm

Code: Select all: 3.7..9..6.....7...82....1...5..6...1...354...7...9..6...5....12...9.....4..2..3.7 b5 - 1 Locked Candidate (1) b8 - 5 Locked Candidate (1) finned Franken Swordfish c17b1\r247 <> 9 [r4c3] +-----------------------------------------------------------------------+ | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | |-----------------------+-----------------------+-----------------------| | 29 5 2348 | 7 6 28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 128 | 2458 6 3458 | |-----------------------+-----------------------+-----------------------| | 69 36789 5 | 468 3478 368 | 4689 1 2 | | 126 13678 12368 | 9 13478 13568 | 4568 458 458 | | 4 1689 1689 | 2 18 1568 | 3 589 7 | +-----------------------------------------------------------------------+

Someone else will have to convert this to NL notation.

Code: Select all: [r4c1]=2 [r4c6]=8 [r37c6]=36 [r89c6]=15 [r9c5]=8 [b7]~169 => [r4c1]<>2

Code: Select all: r8 - 48 Naked Pair c2 - 1347 Naked Quad b1 - 69 Naked Pair r2c9 <> 9 XY-Wing on [r5c2] r8c2 <> 37 Unique Rectangle Type 1

by **hobiwan** » Wed Apr 09, 2008 5:58 pm

Different approach:

Code: Select all: .------------------------.---------------------.---------------------. | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | :------------------------+---------------------+---------------------: | 29 5 23489 | 7 6 28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 128 | 2458 6 3458 | :------------------------+---------------------+---------------------: | C69 3-678-9 5 | 468 3478 368 | 4689 1 2 | | 12-6 13-678 123-68 | 9 13478 13568 | 4568 458 458 | | 4 A1689 A1689 | 2 B18 -156-8 | 3 5-89 7 | '------------------------'---------------------'---------------------'

Sue de Coq: [r9c23] - {1689} ([r9c5] - {18}, [r7c1] - {69}) => [r78c2],[r8c13]<>6, [r7c2]<>9, [r9c6]<>1, [r9c68]<>8
W-Wing: 8 in [r6c4],[r9c5] verbunden durch 1 in [r68c6] => [r7c4]<>8

Code: Select all: .---------------------.-----------------------.---------------------. | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | :---------------------+-----------------------+---------------------: | 29 5 23489 | 7 6 B28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 128 | 2458 6 3458 | :---------------------+-----------------------+---------------------: | 69 378 5 | 46 347-8 A368 | 4689 1 2 | | 12 1378 1238 | 9 -1347-8 A13568 | 4568 458 458 | | 4 1689 1689 | 2 C18 B56 | 3 59 7 | '---------------------'-----------------------'---------------------'

Sue de Coq: [r78c6] - {13568} ([r39c6] - {356}, [r9c5] - {18}) => [r78c5]<>8, [r8c5]<>1
Naked Triple: 3,4,7 in [r378c5] => [r12c5]<>4, [r2c5]<>3
Locked Candidates Type 1 (Pointing): 3 in b2 => [r3c9]<>3
Discontinuous Nice Loop [r4c1]-2-[r4c6]=2=[r6c6]=1=[r8c6]-1-[r8c1]-2-[r4c1] => [r4c1]<>2
Singles
Locked Candidates Type 1 (Pointing): 8 in b9 => [r8c23]<>8
Hidden Triple: 6,8,9 in [r259c2] => [r25c2]<>1, [r2c2]<>4
Naked Pair: 6,9 in [r2c2],[r3c3] => [r2c3]<>6, [r2c3]<>9
W-Wing: 8 in [r5c9],[r9c3] verbunden durch 9 in [r3c39] => [r5c3]<>8
XY-Wing: 8/6/9 in [r25c2],[r5c9] => [r2c9]<>9
Uniqueness Test 1: 3/7 in [r7c25],[r8c25] => [r8c2]<>3, [r8c2]<>7

by **eleven** » Thu Apr 10, 2008 1:49 pm

daj95376 wrote:Someone else will have to convert this to NL notation.
Code: Select all
[r4c1]=2 [r4c6]=8 [r37c6]=36 [r89c6]=15 [r9c5]=8 [b7]~169 => [r4c1]<>2

Suppose you would need 2 big ALS's, hard to read.
But i can easily follow your notation, maybe you should write [r7c1,r9c23]=169 [r8c1]=2 => [r4c1]<>2 at the end.

by **ronk** » Thu Apr 10, 2008 2:36 pm

daj95376 wrote:Someone else will have to convert this to NL notation.

[r4c1]=2 [r4c6]=8 [r37c6]=36 [r89c6]=15 [r9c5]=8 [b7]~169 => [r4c1]<>2

Code: Select all: After SSTS 3 14 7 | 1458 1248 9 | 2458 2458 6 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 8 2 469 | 456 34 B36 | 1 7 3459 --------------------+--------------------+------------------ 9-2 5 23489 | 7 6 A28 | 2489 23489 1 1269 1689 12689 | 3 5 4 | 7 289 89 7 348 2348 | 18 9 128 | 2458 6 3458 --------------------+--------------------+------------------ D69 36789 5 | 468 3478 B368 | 4689 1 2 D126 13678 12368 | 9 13478 B13568 | 4568 458 458 4 D1689 D1689 | 2 C18 B1568 | 3 589 7 A B C D r4c1 -2- r4c6 -8- ALS:r3789c6 -1- r9c5 -8- ALS:[r9c23,r78c1] -2- r4c1 ==> r4c1<>2

With a little more detail ...

r4c1 -2- r4c6 -8- ALS:(r3789c6 =8|1= r89c6) -1- r9c5 -8- ALS:(r9c23 =8|2= r78c1) -2- r4c1 ==> r4c1<>2

by **storm_norm** » Fri Apr 11, 2008 5:31 am

Code: Select all: .6....92. .7.23.8.. ...7.1... 8........ ..56.84.. ........3 ...4.7... ..3.15.6. .92....4.

I'll toss this one in as bonus.

by **Draco** » Sat Apr 12, 2008 2:55 am

storm_norm wrote:
Code: Select all
.6....92. .7.23.8.. ...7.1... 8........ ..56.84.. ........3 ...4.7... ..3.15.6. .92....4.

I'll toss this one in as bonus.

Some bonus... my solver needed 15+ short forcing chains to crack this (I can post if anyone really wants to see that many). Pretty slim pickings for clues...

Cheers,

- drac

by **Carcul** » Sun May 11, 2008 2:28 pm

Code: Select all: *----------------------------------------------------------------* | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | |---------------------+---------------------+--------------------| | 29 5 23489 | 7 6 28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 128 | 2458 6 3458 | |---------------------+---------------------+--------------------| | 69 36789 5 | 468 3478 368 | 4689 1 2 | | 126 13678 12368 | 9 13478 13568 | 4568 458 458 | | 4 1689 1689 | 2 18 1568 | 3 589 7 | *----------------------------------------------------------------*

1) [r9c8]=9=[r7c7]-9-[r7c1]-6-[r9c235]-9-[r9c8], => r7c2<>6,9; r8c123<>6.

2) [r9c6]-1-[r7c1|r9c23]-8-[r9c5]-1-[r9c6], => r9c6<>1.

3) [r9c6]=5=[r8c6]=1=[r6c6]=2=[r4c6]-2-[r4c1]-9-[r7c1]-6-[r9c23]=6=
=[r9c6], => r9c6<>8; r8c6<> 3,6,8; r6c6<>8; r4c3, r4c7, r4c8 <>2; r5c1<>9.

4) [r8c6]-1-[r6c6]-2-[r4c6]=2=[r4c1]-2-[r8c1]-1-[r8c6], => r8c6<>1 and the puzzle is solved.

by **daj95376** » Sun May 11, 2008 11:00 pm

Carcul wrote:
Code: Select all
*----------------------------------------------------------------* | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | |---------------------+---------------------+--------------------| | 29 5 23489 | 7 6 28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 128 | 2458 6 3458 | |---------------------+---------------------+--------------------| | 69 36789 5 | 468 3478 368 | 4689 1 2 | | 126 13678 12368 | 9 13478 13568 | 4568 458 458 | | 4 1689 1689 | 2 18 1568 | 3 589 7 | *----------------------------------------------------------------*

1) [r9c8]=9=[r7c7]-9-[r7c1]-6-[r9c235]-9-[r9c8], => r7c2<>6,9; r8c123<>6.

Carcul: Isn't [r9c6]<>1,8 also part of (1) :?:

by **Glyn** » Mon May 12, 2008 12:54 am

Deleted post as it was incorrect.

by **ronk** » Mon May 12, 2008 1:16 am

daj95376 wrote:
Carcul wrote:1) [r9c8]=9=[r7c7]-9-[r7c1]-6-[r9c235]-9-[r9c8], => r7c2<>6,9; r8c123<>6.

Isn't [r9c6]<>1,8 also part of 1)

Yes. Due to the continuous nature of the loop, all weak links become conjugate links and digits 1 & 8 are locked in the ALS.

r9c8 =9= r7c7 -9- r7c1 -6- ALS:(r9c23 =6|18|9= r9c235) -9- r9c8 = continuous loop,
==> r7c2<>69, r8c123<>6, r9c6<>18, r9c8<>8 [edit: added r9c8<>8]

Carcul, those are two very nice continuous loops.

by **Glyn** » Mon May 12, 2008 1:35 am

Thanks Ronk for coming up with the correct explanation I can see now that from the notation that r9c235 are either {186} or (189} and r9c6<>1,8 either way.

by **daj95376** » Mon May 12, 2008 6:24 am

Code: Select all: *----------------------------------------------------------------* | 3 14 7 | 1458 1248 9 | 2458 2458 6 | | 5 1469 1469 | 1468 12348 7 | 2489 23489 3489 | | 8 2 469 | 456 34 36 | 1 7 3459 | |---------------------+---------------------+--------------------| | 29 5 23489 | 7 6 28 | 2489 23489 1 | | 1269 1689 12689 | 3 5 4 | 7 289 89 | | 7 348 2348 | 18 9 128 | 2458 6 3458 | |---------------------+---------------------+--------------------| | 69 36789 5 | 468 3478 368 | 4689 1 2 | | 126 13678 12368 | 9 13478 13568 | 4568 458 458 | | 4 1689 1689 | 2 18 1568 | 3 589 7 | *----------------------------------------------------------------*

Upon closer inspection, I think ronk is correct that [r9c8]<>8 can be added to Carcul's list of eliminations in chain (1). But, I also think that I was wrong to suggest that [r9c6]<>18 could be added to Carcul's list. If we treat Carcul's chain as a forcing chain with two streams of overlapping eliminations, then it becomes clearer (for me).

Code: Select all: 1a) [r9c8]<>9 [r7c7]=9 [r7c1]=6 [r9c23]<>6 [r9c235]=189 1b) [r9c8]=9 [r9c23]<>9 [r9c235]=168 [r9c2|3]=6 [r7c1]=9

In this interpretation, [r9c6]<>18 and [r9c8]<>8 can be added to Carcul's elimination list based on (1a). However, in (1b) only [r9c8]<>8 can be added to Carcul's elimination list. In order for (1b) to cause [r7c1]=9 and [r9c6]<>18, I believe that it must become a network at [r9c235]=168.

However, if Carcul had started his chain at [r9c6] :idea:

Code: Select all: -5r9c6 5r9c8 9r7c7 6r7c1 6r9c6 5r9c6 6r9c23 9r7c1 -9r7c7 9r9c8

by **Glyn** » Mon May 12, 2008 8:48 am

I think this would produce the eliminations given by Ronk

(189=6)ALS:r9c235-(6=9)r7c1-(9=168)ALS:r9c235

The closure of the loop allows Carcul's eliminations at the peers of the ends of the weak links (ie the 6's and 9's in Box 7 outside the chain). The ends of the chain give the strong link between the values possible in r9c235 leading to Ronk's additional eliminations.

The New Sudoku Players' Forum

interesting one

interesting one