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by **SteveG48** » Thu Nov 24, 2022 4:29 pm

Happy Thanksgiving everyone. Hopefully, this one isn't a turkey.

Code: Select all: *-----------* |8.4|5..|...| |.69|134|...| |.1.|.2.|...| |---+---+---| |.7.|.5.|..9| |..8|261|7..| |3..|.4.|.1.| |---+---+---| |...|.7.|.8.| |...|413|96.| |...|..2|3.4| *-----------*

by **RSW** » Thu Nov 24, 2022 11:14 pm

Code: Select all: +---------------+---------+-----------------+ | 8 b23 4 | 5 9 67 | 126 c237 c12367 | | 257 6 9 | 1 3 4 | 58 257 2578 | | 57 1 357 | 8 2 67 | 4 9 d3567 | +---------------+---------+-----------------+ | 146 7 126 | 3 5 8 | 26 24 9 | | 49 49-5 8 | 2 6 1 | 7 345 e35 | | 3 a25 256 | 7 4 9 | 8-5 1 268-5 | +---------------+---------+-----------------+ | 469 349 36 | 69 7 5 | 12 8 12 | | 257 8 257 | 4 1 3 | 9 6 f57 | | 169 9-5 1567 | 69 8 2 | 3 g57 4 | +---------------+---------+-----------------+

(5=2)r6c2 - (2=3)r1c2 - (3)r1c89 = (3)r3c9 - (3=5)r5c9 - (5)r8c9 = (5)r9c8 => -5r59c2 -5r6c79; stte

Website · by **denis_berthier** » Fri Nov 25, 2022 7:03 am

.
Happy Thanksgiving

Code: Select all: Resolution state after Singles and whips[1]: +-------------------+-------------------+-------------------+ ! 8 23 4 ! 5 9 67 ! 126 237 12367 ! ! 257 6 9 ! 1 3 4 ! 258 257 2578 ! ! 57 1 357 ! 8 2 67 ! 4 9 3567 ! +-------------------+-------------------+-------------------+ ! 1246 7 126 ! 3 5 8 ! 26 24 9 ! ! 459 459 8 ! 2 6 1 ! 7 345 35 ! ! 3 25 256 ! 7 4 9 ! 2568 1 2568 ! +-------------------+-------------------+-------------------+ ! 2469 2349 236 ! 69 7 5 ! 12 8 12 ! ! 257 8 257 ! 4 1 3 ! 9 6 257 ! ! 15679 59 1567 ! 69 8 2 ! 3 57 4 ! +-------------------+-------------------+-------------------+ 115 candidates

1) There's a solution in BC3:

Code: Select all: naked-pairs-in-a-row: r7{c7 c9}{n1 n2} ==> r7c3≠2, r7c2≠2, r7c1≠2 whip[1]: r7n2{c9 .} ==> r8c9≠2 hidden-pairs-in-a-column: c7{n5 n8}{r2 r6} ==> r6c7≠6, r6c7≠2, r2c7≠2 naked-triplets-in-a-column: c1{r2 r3 r8}{n2 n7 n5} ==> r9c1≠7, r9c1≠5, r5c1≠5, r4c1≠2 biv-chain[3]: r3n3{c9 c3} - r7c3{n3 n6} - r6n6{c3 c9} ==> r3c9≠6 singles ==> r3c6=6, r1c6=7 naked-pairs-in-a-row: r1{c2 c8}{n2 n3} ==> r1c9≠3, r1c9≠2, r1c7≠2 naked-triplets-in-a-column: c9{r3 r5 r8}{n7 n3 n5} ==> r6c9≠5, r2c9≠7, r2c9≠5 finned-x-wing-in-columns: n7{c9 c1}{r8 r3} ==> r3c3≠7 whip[1]: c3n7{r9 .} ==> r8c1≠7 biv-chain[3]: r8c1{n5 n2} - b1n2{r2c1 r1c2} - r6c2{n2 n5} ==> r9c2≠5 singles ==> r9c2=9, r9c4=6, r7c4=9, r9c1=1, r4c3=1, r5c1=9 whip[1]: r4n2{c8 .} ==> r6c9≠2 whip[1]: c2n5{r6 .} ==> r6c3≠5 biv-chain[3]: r5n4{c2 c8} - c8n3{r5 r1} - c2n3{r1 r7} ==> r7c2≠4 stte

2) The simplest 1-step solution requires a whip[5]:
whip[5]: r1c2{n2 n3} - r3n3{c3 c9} - r5c9{n3 n5} - b9n5{r8c9 r9c8} - c2n5{r9 .} ==> r6c2≠2
stte

3) There's a 2-step solution in BC4:

Code: Select all: biv-chain[4]: r5c9{n5 n3} - r3n3{c9 c3} - r1c2{n3 n2} - r6c2{n2 n5} ==> r6c7≠5, r6c9≠5, r5c1≠5, r5c2≠5 singles ==> r2c7=5, r2c9=8, r6c7=8 biv-chain[4]: r1c2{n2 n3} - c8n3{r1 r5} - c8n5{r5 r9} - c2n5{r9 r6} ==> r6c2≠2 stte

by **jco** » Fri Nov 25, 2022 8:18 pm

Happy Thanksgiving!
Two steps for me. After basics

Code: Select all: .--------------------------------------------------------------------. | 8 c23 4 | 5 9 67 | 126 237 12367 | | 257 6 9 | 1 3 4 | 58 257 2578 | | 57 1 d357 | 8 2 67 | 4 9 e3567 | |----------------------+----------------------+----------------------| | 16-4 7 126 | 3 5 8 | 26 h24 9 | | 49 a459 8 | 2 6 1 | 7 g35-4 f35 | | 3 25 256 | 7 4 9 | 58 1 2568 | |----------------------+----------------------+----------------------| | 469 b349 36 | 69 7 5 | 12 8 12 | | 257 8 257 | 4 1 3 | 9 6 57 | | 169 59 1567 | 69 8 2 | 3 57 4 | '--------------------------------------------------------------------'

1. (4)r5c2 = (4-3)r7c2 = (3)r1c2 - (3)r3c3 = (3)r3c9 - (3)r5c9 = (3-4)r5c8 = (4)r4c8 => -4 r4c1, -4 r5c8 [4 placements and basics]
---

Code: Select all: .-----------------------------------------------------------. | 8 e2-3 4 | 5 9 67 | 16 237 1367 | |d27 6 9 | 1 3 4 | 5 c27 8 | | 57 1 357 | 8 2 67 | 4 9 367 | |-------------------+-------------------+-------------------| | 16 7 126 | 3 5 8 | 26 4 9 | | 49 a49 8 | 2 6 1 | 7 35 35 | | 3 25 256 | 7 4 9 | 8 1 26 | |-------------------+-------------------+-------------------| | 469 a349 36 | 69 7 5 | 12 8 12 | | 257 8 257 | 4 1 3 | 9 6 57 | | 169 a59 1567 | 69 8 2 | 3 b57 4 | '-----------------------------------------------------------'

2. (3=495)r579c2 - (5=7)r9c8 - (7)r2c8 = (7-2)r2c1 = (2)r1c2 => -3 r1c2; ste

by **SteveG48** » Fri Nov 25, 2022 10:15 pm

Nice, RSW. I like the fact that both eliminations in c2 are necessary for the singles solution.

by **RSW** » Fri Nov 25, 2022 10:23 pm

Thanks. I definitely had to hunt for that one.

by **SteveG48** » Sat Nov 26, 2022 12:03 am

Code: Select all: *--------------------------------------------------------------------* | 8 b23 4 | 5 9 67 | 126 237 12367 | | 257 6 9 | 1 3 4 | 58 257 2578 | | 57 1 a357 | 8 2 67 | 4 9 567-3 | *----------------------+----------------------+----------------------| | 146 7 126 | 3 5 8 | 26 24 9 | | 49 c459 8 | 2 6 1 | 7 345 abe35 | | 3 25 256 | 7 4 9 | 58 1 2568 | *----------------------+----------------------+----------------------| | 469 c349 36 | 69 7 5 | 12 8 12 | | 257 8 257 | 4 1 3 | 9 6 e57 | | 169 d59 1567 | 69 8 2 | 3 d57 4 | *--------------------------------------------------------------------*

3r3c3,r5c9 = (35)r1c2,r5c9 - (3|5=49)r57c2 - (9=57)r9c28 - (7=53)r58c9 => -3 r3c9 ; stte

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