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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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 Posted: Fri Dec 24, 2010 5:14 pm Post subject: Nataraj Special Holiday "NICE" #1 |
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| Code: |
+-------+-------+-------+
| 4 . . | 6 5 . | 3 . . |
| . 6 . | . . . | . . . |
| . . 3 | 7 4 . | . . 9 |
+-------+-------+-------+
| . . . | . . 7 | . . 3 |
| 2 1 . | . 8 . | . 7 5 |
| 7 . . | 5 . . | . . . |
+-------+-------+-------+
| 5 . . | . 7 4 | 2 . . |
| . . . | . . . | . 4 . |
| . . 2 | . 3 1 | . . 8 |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site
| Quote: | X-Wing (9)
Type 3 UR (78), killers create pincers; r1c9<>2 |
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peterj
Joined: 26 Mar 2010
Posts: 974
Location: London, UK
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| Posted: Sat Dec 25, 2010 8:59 am Post subject: |
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| Marty, nice UR pincer move! You can play this without the x-wing for a one-stepper |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Sat Dec 25, 2010 3:55 pm Post subject: |
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I also found the very clean AUR(78) but after viewing Marty's post I went for another solution, which resulted in a fun, long and messy event. No idea what steps were truly useful and what steps were not necessary.
xyz-wing (789)r1c3; r2c3<>8
x-wing(9)r15c39l; r246c3,r26c6<>9
The code at this point is:
| Code: | *-----------------------------------------------------------*
| 4 278 789 | 6 5 289 | 3 1 27 |
| 89 6 57 | 13 129 238 | 458 28 247 |
| 1 258 3 | 7 4 28 | 568 268 9 |
|-------------------+-------------------+-------------------|
| 89 58 4568 | 14 129 7 | 1468 2689 3 |
| 2 1 469 | 34 8 369 | 46 7 5 |
| 7 3 468 | 5 129 26 | 1468 2689 24 |
|-------------------+-------------------+-------------------|
| 5 9 1 | 8 7 4 | 2 3 6 |
| 3 78 78 | 2 6 5 | 9 4 1 |
| 6 4 2 | 9 3 1 | 7 5 8 |
*-----------------------------------------------------------* |
Flightless AXY-wing (57-8) vertex (57)r2c3, pincers (58)r2c7 & (78)r8c3 with fin (4)r2c7; r46c3<>8
If xy-wing is true plus transport: (8)r2c7-r2c1=(8)r4c1;
If fin is true: (4)r2c7-(4=27)b3q36-(2=8)r2c8-r2c1=(8)r4c1;
And now a messy move:
| Code: | *--------------------------------------------------*
| 4 278 789 | 6 5 289 | 3 1 27 |
| 89 6 57 | 13 129 238 | 458 28 247 |
| 1 258 3 | 7 4 28 | 568 268 9 |
|----------------+----------------+----------------|
| 89 58 456 | 14 129 7 | 146 269 3 |
| 2 1 469 | 34 8 369 | 46 7 5 |
| 7 3 46 | 5 19 26 | 18 89 24 |
|----------------+----------------+----------------|
| 5 9 1 | 8 7 4 | 2 3 6 |
| 3 78 78 | 2 6 5 | 9 4 1 |
| 6 4 2 | 9 3 1 | 7 5 8 |
*--------------------------------------------------* |
(8)r6c7=(8-9)r6c8=r4c8-(9=8)r4c1-(8=5)r4c2-r3c2=(5-7)r2c3=(7-4)r2c9=(4-5)r2c7*=(5)r3c7; r2c7*,r3c7<>8
xy-wing 2-69 vertex (29)r4c5; r5c7<>6
Ted |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Mon Dec 27, 2010 4:35 am Post subject: |
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I managed to work out a single-step alternative to my solver's solution. Since Ted didn't post his AUR(78), I don't know if I'm duplicating his effort.
| Code: | before Hidden Triple: dual eliminations on same UR but with different logic
r18c23 <78> UR via s-links on <7> <> 8 r1c3
UR[(2)r1c2 = (9)r1c3] - (9=8)r2c1 <> 8 r1c2
+-----------------------------------------------------------------------+
| 4 *78+2 *78+9 | 6 5 289 | 3 1 27 |
| 89 6 5789 | 13 129 2389 | 458 28 247 |
| 1 258 3 | 7 4 28 | 568 268 9 |
|-----------------------+-----------------------+-----------------------|
| 89 58 45689 | 14 129 7 | 1468 2689 3 |
| 2 1 469 | 34 8 369 | 46 7 5 |
| 7 3 4689 | 5 129 269 | 1468 2689 24 |
|-----------------------+-----------------------+-----------------------|
| 5 9 1 | 8 7 4 | 2 3 6 |
| 3 *78 *78 | 2 6 5 | 9 4 1 |
| 6 4 2 | 9 3 1 | 7 5 8 |
+-----------------------------------------------------------------------+
# 66 eliminations remain
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These eliminations can also be derived through external SIS in [r1], but it relies on a network of interactions for r1c9=7. |
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peterj
Joined: 26 Mar 2010
Posts: 974
Location: London, UK
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| Posted: Mon Dec 27, 2010 9:44 am Post subject: |
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I assumed Marty and Ted's move was this one...
| Code: | | UR(78)[(2)r1c2=(9)r1c3] - (9=8)r2c1 - (8=2)r2c8 ; r1c9<>2 |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Mon Dec 27, 2010 10:09 am Post subject: |
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| That's a lot cleaner than what I found!!! |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Mon Dec 27, 2010 4:21 pm Post subject: |
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That was my move Peter.
Ted |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Mon Dec 27, 2010 4:34 pm Post subject: |
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| I'm pretty sure it was mine too. |
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