The New Sudoku Players' Forum

by **P.O.** » Mon Jul 24, 2023 5:59 pm

Code: Select all: . . 7 . . 9 . 2 1 . 3 1 5 2 . . . . 9 2 . . 7 1 3 5 . . . 5 . 8 . 1 . . 6 . . . . . . 3 . 2 . . . . 4 5 . 6 1 . 2 . . 3 4 . . 7 . . 2 4 . . 1 3 . 4 . . 1 . 2 6 . ..7..9.21.3152....92..7135...5.8.1..6......3.2....45.61.2..34..7..24..13.4..1.26. 458 568 7 3468 36 9 68 2 1 48 3 1 5 2 68 6789 4789 4789 9 2 468 468 7 1 3 5 48 34 79 5 3679 8 267 1 479 2479 6 1789 489 179 59 257 789 3 24789 2 1789 389 1379 39 4 5 789 6 1 5689 2 6789 569 3 4 789 5789 7 5689 689 2 4 568 89 1 3 358 4 389 789 1 578 2 6 5789

by **jco** » Mon Jul 24, 2023 9:59 pm

Code: Select all: .--------------------------------------------------------------------. | 458 568 7 | 3468 B36 9 | 68 2 1 | |*48 3 1 | 5 2 68 | 6789 4789 4789 | | 9 2 46-8 |C468 7 1 | 3 5 C48 | |----------------------+----------------------+----------------------| |*34 79 5 | 3679 8 267 | 1 479 2479 | | 6 1789 489 | 179 59 257 | 789 3 24789 | | 2 1789 A*38(9) | 1379 B39 4 | 5 789 6 | |----------------------+----------------------+----------------------| | 1 5689 2 | 6789 569 3 | 4 789 5789 | | 7 5689 689 | 2 4 568 | 89 1 3 | | 358 4 389 | 789 1 578 | 2 6 5789 | '--------------------------------------------------------------------'

1. Almost Y-wing [(8='3)r6c3 - (3=4)r4c1 - (4=8)r2c1] = (9')r6c3 - (9=36)r16c5 - (6=48)r3c49 => -8 r3c3
---

Code: Select all: .---------------------------------------------------------------------. | *458 568 7 | *3468 36 9 | 68 2 1 | |C*48 3 1 | 5 2 6-8 | 6789 4789 4789 | | 9 2 B46 |A*48(6) 7 1 | 3 5 48 | |----------------------+-----------------------+----------------------| | 34 79 5 | 3679 8 267 | 1 479 2479 | | 6 1789 489 | 179 59 257 | 789 3 24789 | | 2 1789 389 | 1379 39 4 | 5 789 6 | |----------------------+-----------------------+----------------------| | 1 5689 2 | 6789 569 3 | 4 789 5789 | | 7 5689 689 | 2 4 568 | 89 1 3 | | 358 4 389 | 789 1 578 | 2 6 5789 | '---------------------------------------------------------------------'

2. Almost W-wing [(8='4)r3c4 - (4)r1c4 = (4)r1c1 - (4=8)r2c1] = (6')r3c4 - (6=48)b1p29 => -8 r2c6; ste

by **pjb** » Tue Jul 25, 2023 2:48 am

Code: Select all: 458 568 7 | 3468 36 9 | 68 2 1 a48 3 1 | 5 2 b68 | 6789 4789 4789 9 2 d68-4 |c468 7 1 | 3 5 48 ------------------------+----------------------+--------------------- 3-4 79 5 | 3679 8 267 | 1 479 2479 6 1789 e489 | 179 59 257 | 789 3 24789 2 1789 389 | 1379 39 4 | 5 789 6 ------------------------+----------------------+--------------------- 1 5689 2 | 6789 569 3 | 4 789 5789 7 5689 689 | 2 4 568 | 89 1 3 358 4 389 | 789 1 578 | 2 6 5789

(4=8)r2c1 - (8=6)r2c6 - (6)r3c4 = (6-4)r3c3 = (4)r5c3 => -4 r3c3, r4c1 + 8 singles

Code: Select all: 458 568 7 |e468-3 a36 9 |b68 2 1 48 3 1 | 5 2 68 | 6789 4789 4789 9 2 68 |d468 7 1 | 3 5 c48 ------------------------+----------------------+--------------------- 3 79 5 | 679 8 267 | 1 479 2479 6 1789 4 | 179 59 257 | 789 3 2789 2 1789 89 | 1379 39 4 | 5 789 6 ------------------------+----------------------+--------------------- 1 5689 2 | 6789 569 3 | 4 789 5789 7 5689 689 | 2 4 568 | 89 1 3 58 4 3 | 789 1 578 | 2 6 5789

(3=6)r1c5 - (6=8)r1c7 - (8=4)r3c9 - (4)r3c4 = (4-3)r1c4 => -3 r1c4; stte

Phil

by **shye** » Tue Jul 25, 2023 2:55 am

Code: Select all: ,----------------,----------------,-------------------, |*458 568 7 | 3468 36 9 |#68 2 1 | |*48 3 1 | 5 2 #68 | 789-6 4789 4789 | | 9 2 468 | 468 7 1 | 3 5 48 | :----------------+----------------+-------------------: | 34 79 5 | 3679 8 267 | 1 479 2479 | | 6 1789 489 | 179 59 257 | 789 3 24789 | | 2 1789 389 | 1379 39 4 | 5 789 6 | :----------------+----------------+-------------------: | 1 5689 2 | 6789 569 3 | 4 789 5789 | | 7 *5689 *689 | 2 4 *568 |*89 1 3 | |*358 4 389 | 789 1 578 | 2 6 5789 | '----------------'----------------'-------------------'

kite & w-wing fusion

at least one of r12c1 & r8c67 is 8 (else repeat in b7) so
at least one of r1c7 and r2c6 is 6
=> -6r6c7 stte

XSudo Input: Show

points to the person who can find a nice and brief way to notate this

its nice and intuite in my head, although it is rank3...

by **jco** » Tue Jul 25, 2023 2:41 pm

shye wrote:points to the person who can find a nice and brief way to notate this
its nice and intuite in my head, although it is rank3...

W-wing (68) pincers r1c7,r2c6 (doubled) connected by [Kite(8) c1,r8]

Nice move!

by **Hajime** » Tue Jul 25, 2023 3:21 pm

From the initial puzzle

Code: Select all: AIC Type 2 [length 3] (4)4-r1c4=4=r1c1-(4=8)r2c1-(8=6)r2c6 => (-6)r1c4 AIC Type 2 [length 3] (4)(4=8)r2c1-(8=6)r2c6-6-r3c4=6=r3c3 => (-4)r3c3 r5c3=4 Hidden Single in col 3 r4c1=3 Naked Single r9c3=3 Hidden Single in row 9 XY-chain [4 cells] (6)(6=3)r1c5-(3=9)r6c5-(9=8)r6c3-(8=6)r3c3 => (-6)r1c2 (-6)r3c4 r3c3=6 Hidden Single in row 3 NakedPair (89)r8c37 => (-89)r8c2 (-8)r8c6 2-String Kite (8)r3c9=r3c4-r2c6=r9c6 => (-8)r9c9 XY-chain [4 cells] (6)(6=8)r1c7-(8=4)r3c9-(4=8)r3c4-(8=6)r2c6 => (-6)r1c5 (-6)r2c7 stte

All chains are <= 4 in length

by **SteveG48** » Tue Jul 25, 2023 4:37 pm

Code: Select all: *---------------------------------------------------------------------* |e458 568 7 | 3468 36 9 |bd68 2 1 | |f48 3 1 | 5 2 ab6-8 |bc6789 4789 4789 | | 9 2 468 | 468 7 1 | 3 5 48 | *----------------------+----------------------+-----------------------| | 34 79 5 | 3679 8 267 | 1 479 2479 | | 6 1789 489 | 179 59 257 | c789 3 24789 | | 2 1789 389 | 1379 39 4 | 5 789 6 | *----------------------+----------------------+-----------------------| | 1 5689 2 | 6789 569 3 | 4 789 5789 | | 7 d5689 d689 | 2 4 c568 | c89 1 3 | |e358 4 389 | 789 1 578 | 2 6 5789 | *---------------------------------------------------------------------*

6r2c6 = 8r2c6&(6,8)r21c7 - 8r8c6,r258c7 = r1c7&r8c23 - r19c1 = 8r2c1 => -8 r2c6 ; ste

by **Cenoman** » Wed Jul 26, 2023 8:41 pm

shye wrote:kite & w-wing fusion

at least one of r12c1 & r8c67 is 8 (else repeat in b7) so
at least one of r1c7 and r2c6 is 6
=> -6r6c7 stte

points to the person who can find a nice and brief way to notate this
its nice and intuite in my head, although it is rank3...

My two cents...
I see two ways to notate your move:
- Focusing on W-Wings: two almost W-Wings, the spoilers of which are mutually exclusive.
[(6=8)r1c7 - r1c1 = r2c1 - (8=6)r2c6] = r9c1 - r8c23 = [(6=8)r1c7 - r8c7 = r8c6 - (8=6)r2c6] => -6 r2c7
- Focusing on the Kite: [(8)r12c1 = r9c1 - r8c23 = r8c67] - r1c7&r2c6 = (6)r1c7|r2c6 => -6 r2c7

A third compact way is the TM 4x4 (Triangular Matrix).

Code: Select all: 6r1c7 8r1c7 6r2c6 8r2c6 8r1c1 8r2c1 8r9c1 8r8c7 8r8c6 8r8c23 ---------- => -6 r2c7

Edit: corrected typos

by **P.O.** » Thu Jul 27, 2023 5:47 pm

thank you for your answers, my solution:

Code: Select all: 8r1c7 => two 8s in b7 let A be r1c7=8 - r3c9{n8 n4} - 79r2c89 - r2c7{n789 n6} - r2c6{n6 n8} A - c1n8{r2 r9} A - r8n8{c6 c23} => r1c7 <> 8 ste.

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