The New Sudoku Players' Forum

by **eleven** » Sat Oct 16, 2021 4:00 pm

Code: Select all: +-------+-------+-------+ | 4 9 8 | . 1 . | . . . | | . 2 . | . . 3 | 7 . . | | 1 . . | . . . | . 4 . | +-------+-------+-------+ | . 8 . | . . . | . 5 3 | | 6 . . | . . . | . . 2 | | . 3 . | . . . | . 7 6 | +-------+-------+-------+ | 3 . . | . . . | . 9 . | | . 6 . | . . 4 | 5 . . | | 8 5 9 | . 2 . | . . . | +-------+-------+-------+

by **shye** » Sat Oct 16, 2021 5:28 pm

.
after a pair in c8

Code: Select all: .---------------.-----------------------.-----------------. | 4 9 8 | 267 1 267 | 236 236 5 | | 5 2 6 | 489 489 3 | 7 18 189 | | 1 7 3 | 25689 5689 25689 | 268 4 89 | :---------------+-----------------------+-----------------: | 279 8 1247 | 12469 4679 1269 |*149 5 3 | | 6 *14 457-1| 34589-1 345789 589-1 |*489-1 *18 2 | | 29 3 1245 | 124589 4589 12589 |*1489 7 6 | :---------------+-----------------------+-----------------: | 3 *14 24-17| 1568 568 1568 | 28-16 9 178 | |#27 6 #127 | 1389 389 4 | 5 #23 18-7| | 8 5 9 | 1367 2 167 |#136 #36 4 | '---------------'-----------------------'-----------------'

ALS CNL
1r5c2 = 1r7c2 - (1=72)r8c13 - (2=361)b9p578 - 1b6p147 = 1b6p45 - 1r5c2 loop
=> -17r7c3, -16r7c7, -7r8c9, -1r5c3467

then

Code: Select all: .---------------.-----------------------.----------------. | 4 9 8 | 267 1 267 | 236 236 5 | | 5 2 6 | 489 489 3 | 7 #18 #189 | | 1 7 3 | 25689 5689 25689 | 268 4 89 | :---------------+-----------------------+----------------: | 279 8 1247 | 12469 4679 1269 | 149 5 3 | | 6 #14 457 | 34589 345789 589 | 489 #18 2 | | 29 3 1245 | 124589 4589 12589 | 1489 7 6 | :---------------+-----------------------+----------------: | 3 #14 24 | 1568 568 1568 | 28 9 7 | | 27 6 #127 |*389+1 389 4 | 5 23 #18 | | 8 5 9 | 137 2 17 | 136 36 4 | '---------------'-----------------------'----------------'

oddagon
1r258c289b7; guardian 1r8c4
=> +1r8c4 stte

a bit fancier than an x-chain hehe

by **jco** » Sat Oct 16, 2021 6:18 pm

Code: Select all: .--------------------------------------------------------. | 4 9 8 | 267 1 267 | 236 236 5 | | 5 2 6 | 489 489 3 | 7 ga1+8 f189 | | 1 7 3 | 25689 5689 25689 | 26 4 f89 | |---------------+-----------------------+----------------| | 279 8 1247 | 12469 4679 1269 |c149 5 3 | | 6 14 1457 | 134589 345789 1589 |c1489 b18 2 | | 29 3 1245 | 124589 4589 12589 |c1489 7 6 | |---------------+-----------------------+----------------| | 3 14 1247 | 1568 568 1568 | 1268 9 178 | |e27 6 e127 | 1389 389 4 | 5 d23 e178 | | 8 5 9 | 1367 2 167 |d136 d36 4 | '--------------------------------------------------------'

(8)r2c8 = (8-1)r5c8 = (1)r456c7 - (1=632)b9p578 - (2=178)r8c139 - (8)r23c9 = (8)r2c8 => +8 r2c8 ; ste

by **marek stefanik** » Sat Oct 16, 2021 6:58 pm

Code: Select all: .---------------.-----------------------.----------------. | 4 9 8 | 267 1 267 | 236 236 5 | | 5 2 6 | 489 489 3 | 7 18 189 | | 1 7 3 | 25689 5689 25689 | 26 4 89 | :---------------+-----------------------+----------------: | 279 8 1247 | 12469 4679 1269 |#149 5 3 | | 6 #14 1457 | 134589 345789 1589 |#1489 #18 2 | | 29 3 1245 | 124589 4589 12589 |#1489 7 6 | :---------------+-----------------------+----------------: | 3 #14 1247 | 568–1 568 568–1 | 268–1 9 178 | | 27 6 127 | 1389 389 4 | 5 23 178 | | 8 5 9 |#1367 2 #167 |#136 36 4 | '---------------'-----------------------'----------------'

1r9c2b6\r57c7b8 => –1r7c467, btte

Marek

by **Leren** » Sat Oct 16, 2021 7:42 pm

Code: Select all: *--------------------------------------------------------* | 4 9 8 | 267 1 267 | 236 236 5 | | 5 2 6 | 489 489 3 | 7 18 19-8 | | 1 7 3 | 25689 5689 25689 | 26 4 9-8 | |--------------+---------------------+-------------------| | 279 8 1247 | 12469 4679 1269 | 149 5 3 | | 6 14 1457 | 134589 345789 1589 | 1489 18 2 | | 29 3 1245 | 124589 4589 12589 | 1489 7 6 | |--------------+---------------------+-------------------| | 3 14 1247 | 1568 568 1568 | 126-8 9 c178 | |a27 6 a127 | 1389 389 4 | 5 b23 ca178 | | 8 5 9 | 1367 2 167 |c136 c36 4 | *--------------------------------------------------------*

ALS XY Wing: (8=2) r8c139 - (2=3) r8c8 - (3=8) r7c9, r8c9, r9c78 => - 8 r23c9, r7c7; stte

Leren

by **RSW** » Sat Oct 16, 2021 10:23 pm

Code: Select all: +-------------+---------------------+----------------+ | 4 9 8 | 267 1 267 | 236 236 5 | | 5 2 6 | 489 489 3 | 7 *8-1 f189 | | 1 7 3 | 25689 5689 25689 | 26 4 f89 | +-------------+---------------------+----------------+ | 279 8 1247 | 12469 4679 1269 |b149 5 3 | | 6 14 1457 | 134589 345789 1589 |b1489 a18 2 | | 29 3 1245 | 124589 4589 12589 |b1489 7 6 | +-------------+---------------------+----------------+ | 3 14 1247 | 1568 568 1568 | 1268 9 178 | |#27 6 #127 | 1389 389 4 | 5 d##23 e#178 | | 8 5 9 | 1367 2 167 |c#136 #36 4 | +-------------+---------------------+----------------+

ALS(1236)b9p578 & ALS(12378)r8c1389
(1)r5c8 = (1)r456c7 - (1)r9c7 == (2-3)r8c8 == (8)r8c9 - (8)r23c9 = (8)r2c8 => -1r2c8; stte

Website · by **denis_berthier** » Sun Oct 17, 2021 6:33 am

.

Code: Select all: Resolution state after Singles and whips[1]: +----------------------+----------------------+----------------------+ ! 4 9 8 ! 267 1 267 ! 236 236 5 ! ! 5 2 6 ! 489 489 3 ! 7 18 189 ! ! 1 7 3 ! 25689 5689 25689 ! 268 4 89 ! +----------------------+----------------------+----------------------+ ! 279 8 1247 ! 12469 4679 1269 ! 149 5 3 ! ! 6 14 1457 ! 134589 345789 1589 ! 1489 18 2 ! ! 29 3 1245 ! 124589 4589 12589 ! 1489 7 6 ! +----------------------+----------------------+----------------------+ ! 3 14 1247 ! 1568 568 1568 ! 1268 9 178 ! ! 27 6 127 ! 1389 389 4 ! 5 1238 178 ! ! 8 5 9 ! 1367 2 167 ! 136 136 4 ! +----------------------+----------------------+----------------------+

There's a very elementary solution in S3+W3:

Code: Select all: naked-pairs-in-a-column: c8{r2 r5}{n1 n8} ==> r9c8≠1, r8c8≠8, r8c8≠1 z-chain[2]: c2n1{r7 r5} - b6n1{r5c8 .} ==> r7c7≠1 naked-triplets-in-a-block: b3{r2c8 r2c9 r3c9}{n8 n1 n9} ==> r3c7≠8 whip[3]: r9n1{c6 c7} - b6n1{r6c7 r5c8} - c2n1{r5 .} ==> r7c6≠1 whip[3]: r9n1{c6 c7} - b6n1{r6c7 r5c8} - c2n1{r5 .} ==> r7c4≠1 naked-triplets-in-a-block: b8{r7c4 r7c5 r7c6}{n5 n6 n8} ==> r9c6≠6, r9c4≠6, r8c5≠8, r8c4≠8 stte

There are two 1-step solutions in W7, but that's too complicated patterns for such an easy puzzle:

Code: Select all: whip[7]: r8c1{n2 n7} - r8c3{n7 n1} - c2n1{r7 r5} - r5c8{n1 n8} - r2c8{n8 n1} - c9n1{r2 r7} - r7n7{c9 .} ==> r7c3≠2 stte

OR:

Code: Select all: whip[7]: r8c1{n2 n7} - r8c3{n7 n1} - c2n1{r7 r5} - r5c8{n1 n8} - r2c8{n8 n1} - c9n1{r2 r7} - r7n7{c9 .} ==> r8c8≠2 stte

I prefer a 2-step solution that uses only short chains:

Code: Select all: naked-triplets-in-a-block: b3{r2c8 r2c9 r3c9}{n8 n1 n9} ==> r3c7≠8 whip[4]: r7n2{c7 c3} - r8c1{n2 n7} - r8c3{n7 n1} - r8c9{n1 .} ==> r7c7≠8 stte

OR:

Code: Select all: naked-pairs-in-a-column: c8{r2 r5}{n1 n8} ==> r8c8≠8, r9c8≠1, r8c8≠1 whip[4]: r7n2{c7 c3} - r8c1{n2 n7} - r8c3{n7 n1} - r8c9{n1 .} ==> r7c7≠8 whip[1]: b9n8{r8c9 .} ==> r2c9≠8, r3c9≠8 stte

OR:

Code: Select all: whip[4]: r7n2{c7 c3} - r8c1{n2 n7} - r8c3{n7 n1} - r8c9{n1 .} ==> r7c7≠8 whip[4]: c7n8{r6 r3} - r3c9{n8 n9} - r2c9{n9 n1} - r2c8{n1 .} ==> r5c8≠8 stte

by **P.O.** » Sun Oct 17, 2021 8:20 am

Code: Select all: after singles and intersections: 4 9 8 267 1 267 236 236 5 5 2 6 489 489 3 7 d(18) 189 1 7 3 25689 5689 25689 268 4 89 279 8 1247 12469 4679 1269 149 5 3 6 14 1457 134589 345789 1589 1489 d(18) 2 29 3 1245 124589 4589 12589 1489 7 6 3 14 1247 b1+(568) b+(568) b1+(568) e+1-(268) 9 ×178 27 6 127 c18+(39) c8+(39) 4 5 d+2-(×138) ×178 8 5 9 a*1367 2 a*167 ea-1(36) ea-1(36) 4

r9n1{c7c8 c4c6} - r7{c4c5c6}{n5n6n8} - r8{c4c5}{n3n9} - r8c8{n1n3n8 n2} - r7c7{n2n6n8 n1} => r7c9 r8c8 r8c9 <> 1
ste.

D