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daj95376
Joined: 23 Aug 2008
Posts: 3854
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 Posted: Fri Jul 09, 2010 10:32 am Post subject: Puzzle 10/07/09: turbot |
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| Code: | +-----------------------+
| . 2 4 | . . 6 | 9 1 . |
| 9 . 3 | . . . | . . 6 |
| 8 1 6 | 9 3 . | . . . |
|-------+-------+-------|
| . . 2 | . . . | . . . |
| . . 5 | . 6 2 | . . 9 |
| 1 . . | . 9 3 | . 2 5 |
|-------+-------+-------|
| 6 . . | . . . | 5 . . |
| 2 . . | . . 4 | . . . |
| . 4 . | . 5 9 | . . 1 |
+-----------------------+
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Play this puzzle online at the Daily Sudoku site
| Code: | after basics
+-----------------------------------------------------------------------+
| 5 2 4 | 78 78 6 | 9 1 3 |
| 9 7 3 | 24 24 1 | 8 5 6 |
| 8 1 6 | 9 3 5 | 247 47 247 |
|-----------------------+-----------------------+-----------------------|
| 347 9 2 | 5 1478 78 | 13467 34678 478 |
| 347 38 5 | 1478 6 2 | 1347 3478 9 |
| 1 6 78 | 478 9 3 | 47 2 5 |
|-----------------------+-----------------------+-----------------------|
| 6 38 19 | 12378 1278 78 | 5 34789 2478 |
| 2 5 19 | 13678 178 4 | 367 36789 78 |
| 37 4 78 | 2368 5 9 | 236 368 1 |
+-----------------------------------------------------------------------+
# 81 eliminations remain
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Fri Jul 09, 2010 8:02 pm Post subject: |
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A fun puzzle ......
| Quote: |
Grounded(flightless?) skyscraper 8 r7c26 with transport (8)r5c2-r6c3=(8)r6c4; r4c6,r5c4<>8
Coloring 8 r7c4589,r9c8<>8
xy-wing 34-8 with vertex r4c1; r5c8<>8
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Ted |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Fri Jul 09, 2010 11:32 pm Post subject: |
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Love that "grounded" skyscraper Ted  I stared at this puzzle for some while and missed it + the extension/transport.  |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Sat Jul 10, 2010 12:43 am Post subject: |
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| tlanglet wrote: | Grounded(flightless?) skyscraper 8 r7c26 with transport (8)r5c2-r6c3=(8)r6c4; r4c6,r5c4<>8
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How about ...
(8): r4c6 = r7c6 - r7c2 = r5c2- r6c3 = r6c4 - loop; r4c5,r5c4,r7c4589<>8 |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Sat Jul 10, 2010 4:22 am Post subject: |
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| daj95376 wrote: | | tlanglet wrote: | Grounded(flightless?) skyscraper 8 r7c26 with transport (8)r5c2-r6c3=(8)r6c4; r4c6,r5c4<>8
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How about ...
( : r4c6 = r7c6 - r7c2 = r5c2- r6c3 = r6c4 - loop; r4c5,r5c4,r7c4589<>8 |
Thanks for pointing out the loop condition Danny. I saw the x-chain 8 but immediately viewed it as both ends, r4c6 & r6c4, equal to 8 and did not think through the overall circumstances. I consider it another lesson, and only hope that I have learned it well.
Ted |
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kcplayer
Joined: 30 Jun 2010
Posts: 6
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| Posted: Wed Jul 14, 2010 8:07 pm Post subject: |
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I am trying to understand the skyscraper technique when I come across this discussion. I am a bit confuse with the posting. I believe with
8 r7c26 with transport (8)r5c2-r6c3=(8)r6c4
this will make r4c5 and r5c4 not 8, also why is the r4c6 colour red, what is the significant of r4c6. I though this can be 8 if r7c2 is 8, would you also explain why "Coloring 8 r7c4589 make r9c8 not 8 "?
Thanks in advance |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Wed Jul 14, 2010 8:44 pm Post subject: |
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| kcplayer wrote: | I am trying to understand the skyscraper technique when I come across this discussion. I am a bit confuse with the posting. I believe with
8 r7c26 with transport (8)r5c2-r6c3=(8)r6c4
this will make r4c5 and r5c4 not 8, also why is the r4c6 colour red, what is the significant of r4c6. I though this can be 8 if r7c2 is 8, would you also explain why "Coloring 8 r7c4589 make r9c8 not 8 "?
Thanks in advance |
Hello kcplayer,
Ted's original post contained a typographical error. When I quoted his post, I marked the typo in red. When I listed the results of my loop, I included the correct cell in blue.
Regards, Danny
[Edit: dropped last paragraph as not relevant.]
Last edited by daj95376 on Thu Jul 15, 2010 12:20 am; edited 1 time in total |
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kcplayer
Joined: 30 Jun 2010
Posts: 6
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| Posted: Wed Jul 14, 2010 11:30 pm Post subject: |
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| Thanks, Danny I study it some more and understand the r7c4589<>8. Unfortunately I still don't get the last part which is xy-wing 34-8 with vertex r4c1 that lead to r5c6 <>8, I like to know the 3 boxes of the xy-wing |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu Jul 15, 2010 12:06 am Post subject: |
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Okay, you are working from Ted's solution and I completely ignored it because of your reference to red.
Step 1: Multi-Colors on <8>
| Code: | Pink: r4c6
Amber: r7c6
Blue: r6c3,r7c2
Green: r5c2,r6c4,r9c3
Eliminations found: r4c5,r5c4
Eliminations missed: r7c4589
+-----------------------------------+
| . . . | 8 8 . | . . . |
| . . . | . . . | 8 . . |
| 8 . . | . . . | . . . |
|-----------+-----------+-----------|
| . . . | . -8 P8 | . 8 8 |
| . G8 . | -8 . . | . 8 . |
| . . B8 | G8 . . | . . . |
|-----------+-----------+-----------|
| . B8 . | 8 8 A8 | . 8 8 |
| . . . | 8 8 . | . 8 8 |
| . . G8 | 8 . . | . 8 . |
+-----------------------------------+
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Step 2: Colors on <8>
| Code: | Blue: r4c6,r5c8,r6c3,r7c2
Green: r5c2,r6c4,r7c6,r9c3
Eliminations found: r7c4589,r9c8
+-----------------------------------+
| . . . | 8 8 . | . . . |
| . . . | . . . | 8 . . |
| 8 . . | . . . | . . . |
|-----------+-----------+-----------|
| . . . | . . B8 | . 8 8 |
| . G8 . | . . . | . B8 . |
| . . B8 | G8 . . | . . . |
|-----------+-----------+-----------|
| . B8 . | -8 -8 G8 | . -8 -8 |
| . . . | 8 8 . | . 8 8 |
| . . G8 | 8 . . | . -8 . |
+-----------------------------------+
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After several basic steps,
Step 3: <34+8> XY-Wing r4c1/r4c9+r5c2; r5c8<>8
| Code: | *---------------------------------------------------------------------*
| 5 2 4 | 7 8 6 | 9 1 3 |
| 9 7 3 | 24 24 1 | 8 5 6 |
| 8 1 6 | 9 3 5 | 247 47 247 |
|-----------------------+----------------------+----------------------|
| v34 9 2 | 5 147 78 | 1346 3468 p48 |
| 347 p38 5 | 14 6 2 | 1347 347-8 9 |
| 1 6 78 | 48 9 3 | 47 2 5 |
|-----------------------+----------------------+----------------------|
| 6 38 19 | 123 127 78 | 5 3479 247 |
| 2 5 19 | 136 17 4 | 367 36789 78 |
| 37 4 78 | 2368 5 9 | 236 36 1 |
*---------------------------------------------------------------------*
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kcplayer
Joined: 30 Jun 2010
Posts: 6
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| Posted: Thu Jul 15, 2010 4:30 pm Post subject: |
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| Danny, after looking your solution, it stills take me a while to get it. This is one of the more difficult sudoku I encountered. Thanks for showing my way. I guess this one is best solved by color because the large amount elimination of 8. Is skyscaper do the similar thing ? |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu Jul 15, 2010 6:16 pm Post subject: |
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| kcplayer wrote: | | Danny, after looking your solution, it stills take me a while to get it. This is one of the more difficult sudoku I encountered. Thanks for showing my way. I guess this one is best solved by color because the large amount elimination of 8. Is skyscaper do the similar thing ? |
This puzzle has numerous possible eliminations -- especially for <8>. Here's what's needed to solve the grid.
| Code: | c26r7 Skyscraper/Sashimi X-Wing <> 8 r5c4 (exposes Kite)
r5c3 2-String Kite <> 8 r9c8 (exposes X-Wing)
r69 X-Wing <> 8 r178c4 (forces r1c4=7)
r4 b5 Locked Candidate 1 <> 7 r4c1789 (exposes XY-Wing)
<34+8> XY-Wing r4c1/r4c9+r5c2 <> 8 r5c8 (forces r5c2=8)
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Since Locked Candidate 1 is only a basic step, this puzzle doesn't qualify as BBDB. |
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