| View previous topic :: View next topic |
| Author |
Message |
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
 Posted: Sat Mar 26, 2011 6:32 pm Post subject: Puzzle 11/03/26: ~ Difficult++ |
 |
|
This puzzle has so many alternative solutions that BBDB doesn't begin to describe it.
| Code: | +-----------------------+
| . . 9 | . 5 . | . 2 3 |
| . . 7 | . . . | 8 . . |
| 6 1 3 | 2 9 8 | . . . |
|-------+-------+-------|
| . . 5 | 6 7 . | . 1 . |
| 1 . 8 | 4 3 5 | 2 . 6 |
| . . 6 | . 2 . | . . . |
|-------+-------+-------|
| . 5 . | . 1 . | . . . |
| 8 . . | 9 . . | . 5 . |
| 9 . . | . 8 . | . . 2 |
+-----------------------+
|
Play this puzzle online at the Daily Sudoku site |
|
| Back to top |
|
 |
JC Van Hay
Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
|
| Posted: Sat Mar 26, 2011 7:24 pm Post subject: |
|
|
| Quote: | | (6=19)r1c7,r2c9-9r7c9=9r7c7 => r7c7<>6 |
|
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Sat Mar 26, 2011 9:29 pm Post subject: |
|
|
As JC's solution demonstrated, I failed to check for simple chains that might crack the puzzle. _  _
Maybe this puzzle will be a little more interesting.
| Code: | +-----------------------+
| 2 9 . | . . 7 | 6 8 . |
| 8 4 1 | . . . | . 7 2 |
| . 6 . | . . . | 1 . 9 |
|-------+-------+-------|
| . . . | 8 7 . | . . . |
| . . . | 9 3 . | . . 8 |
| 9 . . | . . 1 | . . . |
|-------+-------+-------|
| 7 . 9 | . . . | 8 . . |
| 4 2 . | . . . | . 9 1 |
| . 3 8 | . 9 . | . 4 6 |
+-----------------------+
|
Play this puzzle online at the Daily Sudoku site |
|
| Back to top |
|
|
JC Van Hay
Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
|
| Posted: Sun Mar 27, 2011 12:07 am Post subject: |
|
|
Entertaining puzzle ...
| Code: | 6 "native" SIS "complex" AIC (coupling between an AFXWing on 3s and an ER on 5s) :
FinnedXWing[3r34c1 3r346c8]=(3-2)r7c8=2r9c7-(2=5)r9c6-(EmptyRectangle)"5r9c1=5r7c2-5r7c9=5r4c9"
=> Derived SIS : 1. [5r9c1,5r4c9] => -5r4c1, 2. [2r7c8,5r7c2] => -5r7c8, 3. [3r4c1,3r46c8,5r4c9] => -3r4c9
=> r4c9=5 and Singles To The End. |
|
|
| Back to top |
|
|
peterj
Joined: 26 Mar 2010
Posts: 974
Location: London, UK
|
| Posted: Sun Mar 27, 2011 7:55 am Post subject: |
|
|
This seemed to solve pretty much with turbot/fish moves on 5 for me (though ones was grouped) ... no less fun for it
| Code: | x-wing(5) c2, c9 ; r4c1368<>5, r7c4568<>5
colouring(5)/x-chain(5) ; (5)r9c1=r7c2 - r7c9=r4c9 - r56c8=r3c8 ; r3c1<>5
x-wing(5) c1, c6 ; r5c7<>5, r9c47<>5
xy-wing(25-7) r9c6 ; r8c7<>7, r9c4<>7 |
JC, nice pattern combo! |
|
| Back to top |
|
|
tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
|
| Posted: Sun Mar 27, 2011 2:41 pm Post subject: |
|
|
I found another one step solution for the original puzzle but my best description for is an "almost" xy-chain. Assume (26=4)r7c6.
If r7c6=26, then: (9=6)r2c8-r1c7=r1c6-(6=2)r7c6-(2=4)r7c3-(4=9)r7c9; r2c9<>9=1
If r7c6=4, then: (4)r7c6-(4=9)r7c9; r2c9<>9=1
Ted |
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Sun Mar 27, 2011 3:10 pm Post subject: |
|
|
Since the finned X-Wing has already been mentioned by JC for the second puzzle, I'm going to add my 2-cents worth.
First, consider the potential X-Wing in c18\r34 for <3>. There are two fin cells associated with this X-Wing, r6c8 and r7c8. This makes r4c9<>3 the most advantageous elimination because r6c8 would be a direct fin cell for it. This leaves dealing with the indirect fin cell, r7c8.
Now, I could try to fold r7c8=3 into a single-step solution, but I notice: (3)r7c8 - r7c9 = (3)r4c9 actually contradicts the premise that r7c8=3 will naturally force r4c9<>3. So, if I'm still to obtain the elimination r4c9<>3, then my best recourse is to first show r7c8<>3.
Two Steps:
| Code: | (35=7)r7c9,r8c7 - (7=5)r8c4 - (5-2)r9c6 - r9c7 = (2)r7c8 => r7c8<>3
finned X-Wing c18\r34 w/ "direct" fin cell r6c8 => r4c9<>3
+-----------------------------------------------------------------------+
| 2 9 35 | 135 15 7 | 6 8 4 |
| 8 4 1 | 356 56 9 | 35 7 2 |
| *35 6 7 | 24 248 248 | 1 *35 9 |
|-----------------------+-----------------------+-----------------------|
| *1356 15 2345 | 8 7 2456 | 9 *12356 5-3 |
| 156 7 245 | 9 3 2456 | 245 1256 8 |
| 9 8 2345 | 2456 2456 1 | 2345 #2356 7 |
|-----------------------+-----------------------+-----------------------|
| 7 15 9 | 12456 12456 23456 | 8 @235 35 |
| 4 2 6 | 57 58 358 | 357 9 1 |
| 15 3 8 | 1257 9 25 | 257 4 6 |
+-----------------------------------------------------------------------+
# 86 eliminations remain
|
Yes Keith, this is a backdoor solution. _  _ |
|
| Back to top |
|
|
tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
|
| Posted: Sun Mar 27, 2011 4:02 pm Post subject: |
|
|
I may have to repeat basics for the second puzzle.......
xy-wing (15-2) vertex (15)r9c1 with als pincer: (2=5)r9c6-(5=1)r9c1-(1=5)r7c2-als(35=2)r7c89; r7c456,r9c7<>2
coloring (3) completes the puzzle
Ted |
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Sun Mar 27, 2011 4:39 pm Post subject: |
|
|
| tlanglet wrote: | xy-wing (15-2) vertex (15)r9c1 with als pincer: (2=5)r9c6-(5=1)r9c1-(1=5)r7c2-als(35=2)r7c89; r7c456,r9c7<>2
coloring (3) completes the puzzle
|
How about renaming it a W-Wing with an als pincer:
(2=5)r9c6 - r9c1=r7c2 - als(35=2)r7c98; r7c456,r9c7<>2 |
|
| Back to top |
|
|
tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
|
| Posted: Sun Mar 27, 2011 5:05 pm Post subject: |
|
|
| daj95376 wrote: | How about renaming it a W-Wing with an als pincer:
|
Fine by me. I gave up worrying about names a long time ago......
Ted |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
