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ravel
Joined: 21 Apr 2006 Posts: 536
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Posted: Tue Dec 04, 2007 2:30 pm Post subject: One from Patterns Game |
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This puzzle by TTHsieh from the current patterns game is very nice to solve (easier than yesterday's).
Code: | 1 . . | . . . | . . 2
. 2 . | 3 . . | . 4 .
. . 5 | . . . | 1 . .
- - - + - - - + - - -
. 6 . | . 7 . | . . .
. . . | 4 8 9 | . . .
. . . | . 1 . | . 5 .
- - - + - - - + - - -
. . 1 | . . . | 7 . .
. 4 . | . . 6 | . 2 .
7 . . | . . . | . . 8
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Johan
Joined: 25 Jun 2007 Posts: 206 Location: Bornem Belgium
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Posted: Tue Dec 04, 2007 7:58 pm Post subject: |
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I found a contradiction in Box 1 when R1C5=4
R1C5=4 => R2C5=6, then we have a potential [89] DP in R28C13, which
means for avoiding the DP R8C1=3 or R8C3=3, but when R8C1=3 we
have a [49] DP in R46C19, and if R8C3=3 it ends up with two <9>'s in
Box 1 => R1C5 <>4, breaking the puzzle wide open.
Code: |
+--------------------------+--------------------------+-------------------------+
| 1 379 349 | 5 469 478 | 369 389 2 |
| 689 2 89 | 3 69 1 | 5 4 7 |
| 3469 379 5 | 89 2 478 | 1 389 36 |
+--------------------------+--------------------------+-------------------------+
| 349 6 349 | 2 7 5 | 8 1 49 |
| 5 1 2 | 4 8 9 | 36 7 36 |
| 49 8 7 | 6 1 3 | 2 5 49 |
+--------------------------+--------------------------+-------------------------+
| 2 39 1 | 89 349 48 | 7 6 5 |
| 389 4 389 | 7 5 6 | 39 2 1 |
| 7 5 6 | 1 39 2 | 4 39 8 |
+--------------------------+--------------------------+-------------------------+
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ravel
Joined: 21 Apr 2006 Posts: 536
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Posted: Tue Dec 04, 2007 10:06 pm Post subject: |
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Wow, this is a Carcul like solution. Using the 2 DP's is interesting. What is your reasoning for Quote: | if R8C3=3 it ends up with two <9>'s in Box 1 | ? I only see
r1c5=4 => r79c5=39 => r2c5=6 => r2c13=89
(r1c5=4 and r8c3=9) => r1c3=9 |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Tue Dec 04, 2007 10:15 pm Post subject: |
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johan,
that is nice !!!
I just spent 30 mins getting to the UR through naked pairs, pointing pairs, etc. |
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Johan
Joined: 25 Jun 2007 Posts: 206 Location: Bornem Belgium
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Posted: Tue Dec 04, 2007 10:47 pm Post subject: |
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Quote: | if R8C3=3 it ends up with two <9>'s in Box 1 |
Ravel,
When R1C5=4, you have a naked [89] pair in R2C13, then R8C3 must be
<3> , for avoiding the [49] DP, leaving a single <9> in R1C3, but <9>
already exists in R2C13. |
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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Tue Dec 04, 2007 11:05 pm Post subject: Pattern's game |
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The 9's in boxes 1-3 can be cleaned up with coloring. Then an xy-chain from R1C3 to R7C2 eliminates the 3 in R1C2 and solves the puzzle.
Earl |
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ravel
Joined: 21 Apr 2006 Posts: 536
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Posted: Wed Dec 05, 2007 11:11 am Post subject: |
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Johan,
thats what i saw, of course my first line above can be shortened to
r1c5=4 => r2c5=6 => r2c13=89.
Earl,
suppose you meant 2 kites for the 9 and an x-wing. The UR and a w-wing also solve it then. |
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re'born
Joined: 28 Oct 2007 Posts: 80
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Posted: Wed Dec 05, 2007 11:20 am Post subject: |
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After basics and a UR single, we get to:
Code: | .---------------.---------------.---------------.
| 1 379 349 | 5 469 478 | 369 389 2 |
| 689 2 89 | 3 69 1 | 5 4 7 |
| 469 379 5 | 89 2 478 | 1 389 36 |
:---------------+---------------+---------------:
| 3 6 49 | 2 7 5 | 8 1 49 |
| 5 1 2 | 4 8 9 | 36 7 36 |
| 49 8 7 | 6 1 3 | 2 5 49 |
:---------------+---------------+---------------:
| 2 39 1 | 89 349 48 | 7 6 5 |
| 89 4 389 | 7 5 6 | 39 2 1 |
| 7 5 6 | 1 39 2 | 4 39 8 |
'---------------'---------------'---------------' |
There is a useless xyz-wing with pivot r8c3 and pincers in r2c3 and r7c2. We conclude one of these three cells is a 9. We now transport the 9's in c3 to the (4)r4c3 and (9)r7c2 is transported to (4)r3c1 via:
(9)r7c2 - (9=8)r7c4 - (8=4)r7c6 - (4)r3c6 = (4)r3c1.
Now any cell that sees r4c3 and r3c1 cannot contain a 4. Hence, r6c1<>4, solving the puzzle.
In Kraken notation:
(9)r7c2 - (9=8)r7c4 - (8=4)r7c6 - (4)r3c6 = (4)r3c1
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(9)r8c3 - (9=4)r4c3
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(9)r2c3 - (9=4)r4c3 |
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ravel
Joined: 21 Apr 2006 Posts: 536
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Posted: Wed Dec 05, 2007 1:32 pm Post subject: |
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I guess i know, how Johan will solve the next one with this pattern
Code: | +-------+-------+-------+
| 1 . . | . . . | . . 2 |
| . 3 . | 1 . . | . 4 . |
| . . 5 | . . . | 6 . . |
+-------+-------+-------+
| . 4 . | . 7 . | . . . |
| . . . | 3 2 6 | . . . |
| . . . | . 5 . | . 1 . |
+-------+-------+-------+
| . . 7 | . . . | 2 . . |
| . 1 . | . . 4 | . 8 . |
| 6 . . | . . . | . . 7 |
+-------+-------+-------+
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Wed Dec 05, 2007 1:40 pm Post subject: |
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uh oh.
we're going to have replies to two different puzzles ...
"I have a bad feeling about this" (The Star Wars films)
"In box 3, the ER in <2>..."
-
"You moron, there's no ER in box 3. You mean the skyscraper on 5" ...
I love this .... |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Wed Dec 05, 2007 2:03 pm Post subject: |
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Don't know what Johan is going to say.
Probably my contribution is also easy to predict:
Medusa coloring on 7 in this position:
Code: |
+--------------------------+--------------------------+--------------------------+
| 1 789 89 | 6 4 5 | 38 37 2 |
| 78 3 6 | 1 9 2 | 578 4 58 |
| 4 2 5 | 8 3 7 | 6 9 1 |
+--------------------------+--------------------------+--------------------------+
| 358 4 38 | 9 7 1 | 358 2 6 |
| 89 57 1 | 3 2 6 | 4 57 89 |
| 279 6 239 | 4 5 8 | 379 1 39 |
+--------------------------+--------------------------+--------------------------+
| 389 89 7 | 5 1 39 | 2 6 4 |
| 235 1 23 | 7 6 4 | 359 8 359 |
| 6 59 4 | 2 8 39 | 1 35 7 |
+--------------------------+--------------------------+--------------------------+
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... just because I've never seen a plot like this in sudoku:
Code: |
+·····+·····+·····+
· *-----------* ·
· /| · · /| ·
·*-----------* | ·
·| | · ·| | ·
·| | · ·| | ·
+|·|··+·····+|·|··+
·| | · ·| | ·
·| | · ·| | ·
·| *-----------* ·
·|/ · ·|/ ·
·*-----------* ·
+·····+·····+·····+
· · · · |
If you look closely ...
if red is true, there can be no "2" in column 1. Thus red is false and the puzzle is solved ... |
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Johan
Joined: 25 Jun 2007 Posts: 206 Location: Bornem Belgium
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Posted: Wed Dec 05, 2007 2:54 pm Post subject: |
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I used the same strategy as the previous one, this time a contradiction in
Box 9.
If R8C1=5, we have a potential [39] DP in R68C79, the only solution for
avoiding this DP is that R6C7 must be <7> => R5C8=5 => R9C8=3, now
we hava a contradiction in Box 9, because <3> already exists in R8C79
=> R8C1<>5.
Code: |
+--------------------------+--------------------------+-------------------------+
| 1 789 89 | 6 4 5 | 378 37 2 |
| 78 3 6 | 1 9 2 | 578 4 58 |
| 4 2 5 | 8 3 7 | 6 9 1 |
+--------------------------+--------------------------+-------------------------+
| 358 4 38 | 9 7 1 | 358 2 6 |
| 5789 5789 1 | 3 2 6 | 4 57 589 |
| 2379 6 239 | 4 5 8 | 379 1 39 |
+--------------------------+--------------------------+-------------------------+
| 389 89 7 | 5 1 39 | 2 6 4 |
| 235 1 23 | 7 6 4 | 359 8 359 |
| 6 59 4 | 2 8 39 | 1 35 7 |
+--------------------------+--------------------------+-------------------------+
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ravel
Joined: 21 Apr 2006 Posts: 536
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Posted: Wed Dec 05, 2007 4:10 pm Post subject: |
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Bingo, i knew, you would spot that
In other words: To avoid the 39-DP either r8c7=5, r8c9=5 or (r6c7=7 =>) r5c8=5. Since r9c8 sees all 3 cells, it cant be 5.
nataraj wrote: | uh oh.
we're going to have replies to two different puzzles ... | Sorry, should have made a new thread |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Wed Dec 05, 2007 4:21 pm Post subject: |
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ravel wrote: | Sorry, should have made a new thread |
nah, NP. didn't think there really would be trouble. Only my imagination running wild |
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