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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Wed Jul 15, 2009 9:17 pm Post subject: Set XY_03 Puzzle 026 |
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Code: | +-----------------------+
| . . 3 | 4 8 . | . . 9 |
| . 5 . | . . . | . . 3 |
| 9 . 7 | . . . | . . . |
|-------+-------+-------|
| 6 . . | 1 . 8 | 7 . 5 |
| 7 . . | . 4 9 | . 6 8 |
| . . . | 3 7 . | . . . |
|-------+-------+-------|
| . . . | 9 . . | 3 . . |
| . . . | . 5 . | . 9 . |
| 8 2 . | 7 3 . | . . . |
+-----------------------+
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Play this puzzle online at the Daily Sudoku site |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Thu Jul 16, 2009 8:02 pm Post subject: |
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Dan: I cleared your message after the confusion was resolved. (okay?)
Everyone: This puzzle should normally be very difficult using traditional techniques. However, I managed to get it to crack after a few steps by using an Atypical Extension of Non-Productive Skyscraper. |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Sat Jul 18, 2009 8:40 am Post subject: |
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Code: | .---------------------.---------------------.---------------------.
| 12 16 3 | 4 8 5 | 126 7 9 |
| 124 5 1268 | 26 9 7 | 12468 124 3 |
| 9 468 7 | 26 1 3 | 24568 245 246 |
:---------------------+---------------------+---------------------:
| 6 9 4 | 1 2 8 | 7 3 5 |
| 7 3 12 | 5 4 9 | 12 6 8 |
| 125 18 1258 | 3 7 6 | 9 124 124 |
:---------------------+---------------------+---------------------:
| 145 147 15 | 9 6 124 | 3 8 1247 |
| 3 1467 16 | 8 5 124 | 124 9 1247 |
| 8 2 9 | 7 3 14 | 1456 145 146 |
'---------------------'---------------------'---------------------' |
ER 1
sky 2
xy {168}
gets the grid to
Code: | .------------------.------------------.------------------.
|*12 *16 3 | 4 8 5 |1-26 7 9 |
| 124 5 8 | 26 9 7 | 1246 124 3 |
| 9 46 7 | 26 1 3 | 8 5 24 |
:------------------+------------------+------------------:
| 6 9 4 | 1 2 8 | 7 3 5 |
| 7 3 12 | 5 4 9 |*12 6 8 |
| 15 8 125 | 3 7 6 | 9 124 *124 |
:------------------+------------------+------------------:
| 145 U147 15 | 9 6 124 | 3 8 U1247 |
| 3 U147 6 | 8 5 124 | 124 9 U1247 |
| 8 2 9 | 7 3 14 | 5 14 6 |
'------------------'------------------'------------------' |
UR17r78c29 says that the 1 in r1c2 and the 1 in r6c9 can't both be false
(2=1)r1c1 - UR17[(1)r1c2 = (1)r6c9] - (1=2)r5c7; r1c7 <> 2
Code: | .------------------.------------------.------------------.
| 2 *16 3 | 4 8 5 | 16 7 9 |
|*14 5 8 | 26 9 7 | 1246 124 3 |
| 9 *46 7 | 26 1 3 | 8 5 *24 |
:------------------+------------------+------------------:
| 6 9 4 | 1 2 8 | 7 3 5 |
| 7 3 12 | 5 4 9 | 12 6 8 |
| 15 8 125 | 3 7 6 | 9 124 *12-4 |
:------------------+------------------+------------------:
| 145 U147 15 | 9 6 124 | 3 8 U1247 |
| 3 U147 6 | 8 5 124 | 124 9 U1247 |
| 8 2 9 | 7 3 14 | 5 14 6 |
'------------------'------------------'------------------' |
UR17r78c29 says that the 1's in r1c2 and r6c9 can't both be false
(4)r3c9 = (4)r3c2 - (4=1)r2c1 - UR17[(1)r1c2 = (1)r6c9]; r7c9 <> 4 |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Sat Jul 18, 2009 5:32 pm Post subject: |
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storm_norm wrote: | Code: | .------------------.------------------.------------------.
|*12 *16 3 | 4 8 5 |1-26 7 9 |
| 124 5 8 | 26 9 7 | 1246 124 3 |
| 9 46 7 | 26 1 3 | 8 5 24 |
:------------------+------------------+------------------:
| 6 9 4 | 1 2 8 | 7 3 5 |
| 7 3 12 | 5 4 9 |*12 6 8 |
| 15 8 125 | 3 7 6 | 9 124 *124 |
:------------------+------------------+------------------:
| 145 U147 15 | 9 6 124 | 3 8 U1247 |
| 3 U147 6 | 8 5 124 | 124 9 U1247 |
| 8 2 9 | 7 3 14 | 5 14 6 |
'------------------'------------------'------------------' |
UR17r78c29 says that the 1 in r1c2 and the 1 in r6c9 can't both be false
(2=1)r1c1 - UR17[(1)r1c2 = (1)r6c9] - (1=2)r5c7; r1c7 <> 2
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I like it !!! |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Sat Jul 18, 2009 7:56 pm Post subject: |
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I did not find this puzzle especially difficult using traditional techniques (unless I cheated somewhere along the line), but I did find it long and FUN. Another BBDB for me using eight steps...........
ER 1,
skyscraper 2,
Type 6 UR 15,
xy-wing 16-8
two ERs on 4,
xy-wing 16-2 with a short extension (or pseudo-cell),
a chain that I found again looking for an extended xy-wing -146
Ted |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Sat Jul 18, 2009 11:15 pm Post subject: |
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tlanglet wrote: | I did not find this puzzle especially difficult using traditional techniques (unless I cheated somewhere along the line), but I did find it long and FUN. Another BBDB for me using eight steps...........
ER 1,
skyscraper 2,
Type 6 UR 15,
xy-wing 16-8
two ERs on 4,
xy-wing 16-2 with a short extension (or pseudo-cell),
a chain that I found again looking for an extended xy-wing -146
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Admirable Ted !!!
My solver found an almost identical solution. The only reason I posted the puzzle was because I found a shortcut using my Atypical approach. I'll post it after Marty and others have a chance to post their solutions. |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Sat Jul 18, 2009 11:22 pm Post subject: |
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Norm, I was reviewing your second PM (for the first time) and it hit me that you missed the chance for a UR link using a hidden pair !!! (Here it is using your first PM)
Code: | (1)r6c9 = (24)r36c9 - UR{(24)r78c9 = (4)r78c2} - (4)r3c2 = (4)r3c9 => [r6c9]<>4
+--------------------------------------------------------------+
| 12 16 3 | 4 8 5 | 126 7 9 |
| 124 5 8 | 26 9 7 | 1246 124 3 |
| 9 46 7 | 26 1 3 | 8 5 (24) |
|--------------------+--------------------+--------------------|
| 6 9 4 | 1 2 8 | 7 3 5 |
| 7 3 12 | 5 4 9 | 12 6 8 |
| 15 8 125 | 3 7 6 | 9 124 1(24) |
|--------------------+--------------------+--------------------|
| 145 17+4 15 | 9 6 124 | 3 8 17+24 |
| 3 17+4 6 | 8 5 124 | 124 9 17+24 |
| 8 2 9 | 7 3 14 | 5 14 6 |
+--------------------------------------------------------------+
# 45 eliminations remain
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No, I don't guarantee that my notation is correct. I'm luck to even be in the ballpark! |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Mon Jul 20, 2009 1:43 pm Post subject: |
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Just because ...
Code: | r8 b7 Locked Candidate 1 <> 6 [r8c79]
r5 b3 Empty Rectangle <> 1 [r2c3]
r15c7 Skyscraper <> 2 [r2c3],[r6c1]
XY-Wing [r1c2]/[r2c3]+[r6c2] <> 8 [r3c2],[r6c3]
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Shortcut using Atypical approach cracks puzzle from either of two starting cells
Code: | | -------------- peers -------------- |
(4)r2c1 = (4-6)r3c2 = r1c2 - r1c7 = (6-4)r2c7 => [r2c7]<>4
(4)r3c9 | ------ Skyscraper ----- |
+--------------------------------------------------------------+
| 12 *16 3 | 4 8 5 | *126 7 9 |
| @124 5 8 | 26 9 7 | *126-4 124 3 |
| 9 *46 7 | 26 1 3 | 8 5 @24 |
|--------------------+--------------------+--------------------|
| 6 9 4 | 1 2 8 | 7 3 5 |
| 7 3 12 | 5 4 9 | 12 6 8 |
| 15 8 125 | 3 7 6 | 9 124 124 |
|--------------------+--------------------+--------------------|
| 145 147 15 | 9 6 124 | 3 8 1247 |
| 3 147 6 | 8 5 124 | 124 9 1247 |
| 8 2 9 | 7 3 14 | 5 14 6 |
+--------------------------------------------------------------+
# 45 eliminations remain
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-or- A more traditional completion
Code: | c17r2 Skyscraper <> 4 [r7c9],[r8c2]
r7 b7 Locked Candidate 1 <> 4 [r7c6]
r67c13 <15> UR Type 6 <> 5 [r6c3],[r7c1]
r78c29 <17> UR via s-link <> 1 [r7c9]
{ 6} -7r7c9 2r7c9 4r3c9 6r3c2 1r1c2 7r8c2 [XY-Chain] <> 7 [r7c2],[r8c9]
{ 3} -2r1c1 1r1c1 6r1c2 4r3c2 2r3c9 [XY-Chain] <> 2 [r1c7]
XYZ-Wing [r2c8]/[r2c1]+[r3c9] <> 4 [r2c7]
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Wed Jul 22, 2009 12:16 am Post subject: |
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daj95376 wrote: | Norm, I was reviewing your second PM (for the first time) and it hit me that you missed the chance for a UR link using a hidden pair !!! (Here it is using your first PM)
Code: | (1)r6c9 = (24)r36c9 - UR{(24)r78c9 = (4)r78c2} - (4)r3c2 = (4)r3c9 => [r6c9]<>4
+--------------------------------------------------------------+
| 12 16 3 | 4 8 5 | 126 7 9 |
| 124 5 8 | 26 9 7 | 1246 124 3 |
| 9 46 7 | 26 1 3 | 8 5 (24) |
|--------------------+--------------------+--------------------|
| 6 9 4 | 1 2 8 | 7 3 5 |
| 7 3 12 | 5 4 9 | 12 6 8 |
| 15 8 125 | 3 7 6 | 9 124 1(24) |
|--------------------+--------------------+--------------------|
| 145 17+4 15 | 9 6 124 | 3 8 17+24 |
| 3 17+4 6 | 8 5 124 | 124 9 17+24 |
| 8 2 9 | 7 3 14 | 5 14 6 |
+--------------------------------------------------------------+
# 45 eliminations remain
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No, I don't guarantee that my notation is correct. I'm luck to even be in the ballpark! |
ahh, I see.
but the {2,4} pair in column 9 doesn't take on a hidden pair type of effect.
the {2,4} pair takes on a naked pair type of effect.
if the 1 is false in r6c9 then the pair {2,4} that is left isn't a hidden pair.
its a naked pair. |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Wed Jul 22, 2009 11:46 am Post subject: |
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storm_norm wrote: | ahh, I see.
but the {2,4} pair in column 9 doesn't take on a hidden pair type of effect.
the {2,4} pair takes on a naked pair type of effect.
if the 1 is false in r6c9 then the pair {2,4} that is left isn't a hidden pair.
its a naked pair. |
I was wondering about that. Thanks for the clarification. |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Thu Jul 23, 2009 12:51 am Post subject: |
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Danny, I made a similar mistake about a week ago. It seems the "words" sometimes just get mixed up.
Ted |
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