The New Sudoku Players' Forum

by **wapati** » Wed Nov 22, 2006 9:45 pm

There is a swordfish but it may be avoided.
Patterns here: xyz, turbot, xy, finned-x, skyscraper.

Code: Select all: . 6 . | 7 . . | . 2 . 8 . . | . . . | . . 1 . . 9 | . 8 . | 4 . . --------------------- 5 . . | . 1 9 | . . . . . 1 | 5 . 8 | 9 . . . . . | 3 4 . | . . 8 --------------------- . . 5 | . 3 . | 1 . . 4 . . | . . . | . . 6 . 9 . | . . 7 | . 4 .

by **wapati** » Wed Nov 22, 2006 9:58 pm

This one has 5 turbots, and that is all you would need.
2 of them are sashimi-x wings, or skyscrapers. Turbot covers
these two patterns.

If you want to you can spot x, xy, finned - x, finned sword and a
sashimi-x instead of the 5 turbots.

Code: Select all: . . 5 | . 4 . | 3 . . . . . | . . 8 | 9 . . 7 . . | 1 . . | . 8 2 --------------------- . . 1 | 5 . . | . 7 . 5 . . | . . . | . . 6 . 2 . | . . 9 | 4 . . --------------------- 3 5 . | . . 4 | . . 1 . . 4 | 3 . . | . . . . . 8 | . 7 . | 6 . .

by **Carcul** » Thu Nov 23, 2006 1:10 am

Wapati wrote:There is a finned swordfish here but it isn't needed.
Turbots and xys, mostly, and an x-wing.

Code: Select all: *-----------------------------------------------------* | 6 1 478 | 48 2 3 | 5 9 478 | | 5 3 2 | 4789 4789 789 | 48 6 1 | | 49 789 478 | 5 1 6 | 3 478 2 | |-----------------+-----------------+-----------------| | 49 789 3 | 2 5 789 | 6 1 48 | | 1 6 578 | 3 78 4 | 2 58 9 | | 2 89 45 | 89 6 1 | 7 45 3 | |-----------------+-----------------+-----------------| | 3 2 9 | 6 48 5 | 1 478 478 | | 8 5 1 | 479 479 2 | 49 3 6 | | 7 4 6 | 1 3 89 | 89 2 5 | *-----------------------------------------------------*

If r8c7=4 then r3c3=4 and r2c7=8 => r1c4=8 => r5c3=8, but that cannot be (why?). So, r9c7=9 and the puzzle is solved.

Carcul

by **re'born** » Thu Nov 23, 2006 1:51 am

wapati wrote:This one has 5 turbots, and that is all you would need.
2 of them are sashimi-x wings, or skyscrapers. Turbot covers
these two patterns.

If you want to you can spot x, xy, finned - x, finned sword and a
sashimi-x instead of the 5 turbots.

Code: Select all: *-----------------------------------------------------------* | 1689 1689 5 | 269 4 26 | 3 16 7 | | 126 136 236 | 7 5 8 | 9 16 4 | | 7 4 69 | 1 369 36 | 5 8 2 | |-------------------+-------------------+-------------------| | 4 369 1 | 5 236 236 | 28 7 89 | | 5 389 39 | 4 238 7 | 1 29 6 | | 68 2 7 | 68 1 9 | 4 3 5 | |-------------------+-------------------+-------------------| | 3 5 269 | 2689 2689 4 | 7 29 1 | | 269 7 4 | 3 269 1 | 28 5 89 | | 129 19 8 | 29 7 5 | 6 4 3 | *-----------------------------------------------------------*

1. r7c5=9 > r7c8 = 2 > r5c8 = 9 > r4c7 = 2, creating a deadly pattern in r34c56. Thus, r7c5 <> 9.

2. AIC: 6[r3c3] = 9[r3c3] - 9[r3c5] = 9[r8c5] - 6[r8c5] = 6[r8c1]
Hence, r7c3 <> 6 (and r12c1 <> 6).

This solves the puzzle.

by **Carcul** » Thu Nov 23, 2006 10:34 am

Wapati wrote:This one has 5 turbots, and that is all you would need.(... finned sword and a sashimi-x instead of the 5 turbots.

Code: Select all: *----------------------------------------------------* | 1689 1689 5 | 269 4 26 | 3 16 7 | | 126 136 236 | 7 5 8 | 9 16 4 | | 7 4 69 | 1 369 36 | 5 8 2 | |-----------------+-----------------+----------------| | 4 369 1 | 5 236 236 | 28 7 89 | | 5 389 39 | 4 238 7 | 1 29 6 | | 68 2 7 | 68 1 9 | 4 3 5 | |-----------------+-----------------+----------------| | 3 5 269 | 2689 2689 4 | 7 29 1 | | 269 7 4 | 3 269 1 | 28 5 89 | | 129 19 8 | 29 7 5 | 6 4 3 | *----------------------------------------------------*

[r3c3]-6-[r7c3]=6=[r8c1]-6-[r6c1]=6=[r6c4]-6-[r4c56]-2-[r4c7]=2=
=[r8c7]-2-[r8c5]-9-[r3c56]-6-[r3c3], => r3c3<>6 solving the puzzle.

Carcul

by **wapati** » Fri Nov 24, 2006 1:15 am

I think a BUG is required for pattern solving.

Pretty odd that it does come up. :!:

Code: Select all: . . .|6 . .|. 1 . . . .|. 3 8|9 . 7 . . .|. 1 5|. 3 . -----+-----+----- 6 . .|. . .|1 5 . . 2 9|. . .|4 7 . . 1 5|. . .|. . 9 -----+-----+----- . 4 .|1 7 .|. . . 5 . 2|8 6 .|. . . . 3 .|. . 2|. . .

by **Carcul** » Fri Nov 24, 2006 1:33 am

Wapati wrote:There is a swordfish but it may be avoided.
Patterns here: xyz, turbot, xy, finned-x, skyscraper.

Code: Select all: *----------------------------------------------------------------* | 13 6 34 | 7 59 1345 | 8 2 359 | | 8 23457 2347 | 2469 2569 23456 | 367 35679 1 | | 1237 12357 9 | 126 8 12356 | 4 3567 357 | |---------------------+---------------------+--------------------| | 5 2348 23468 | 26 1 9 | 2367 367 2347 | | 236 234 1 | 5 7 8 | 9 36 234 | | 9 27 267 | 3 4 26 | 5 1 8 | |---------------------+---------------------+--------------------| | 267 278 5 | 24689 3 246 | 1 789 279 | | 4 12378 2378 | 1289 259 125 | 237 35789 6 | | 1236 9 2368 | 1268 256 7 | 23 4 235 | *----------------------------------------------------------------*

1. [r8c6]=5|6=[r3c4](-6-[r4c4]-2-[r4c79]=2=[r5c9]-2-[r9c9])-6-[r2c5]
=6=[r9c5]-6-[r9c13]=6=[r7c1]=7= [r3c1]-7-[r139c9]-9-[r1c5]-5-[r8c5]
=5=[r8c6], => r8c6=5.

2. [r3c6]=6|3=[r5c1]-3-[r1c1]-1-[r9c1]=1=[r9c4]-1-[r8c4](-9-[r8c5]-2-
-[r2c5])=1|4=[r7c4]-4-[r2c4]-9-[(r2c5)]-6-[r3c6], => r2c6/r3c4<>6 solving the puzzle.

Carcul

by **wapati** » Sun Nov 26, 2006 9:42 pm

JellyFish, my first one that is not trivial to avoid. There are two,
on the same digit but I doubt you can find both. Lots of finned-swords,
if you care to look.

Code: Select all: . . 2 | 5 . 7 | 6 . . . 4 . | . . . | . 5 . . . 5 | 9 . 4 | 2 . . --------------------- 8 . 9 | . . . | 1 . 2 . 5 . | . . . | . 7 . 3 . 4 | . . . | 5 . 6 --------------------- . . 7 | 4 . 9 | 8 . . . 6 . | . . . | . 2 . . . 1 | 2 . 6 | 7 . .

by **Ocean** » Sun Nov 26, 2006 11:01 pm

wapati wrote:JellyFish, my first one that is not trivial to avoid. There are two,
on the same digit but I doubt you can find both. Lots of finned-swords,
if you care to look.

Nice example of a Jellyfish (with Jellyfish also as dual). The Jellyfish is visible at the very beginning, and if applied immediately (or early) the rest is solved by singles.

This puzzle should also qualify as an "Effortless Extreme" - as far as I can read the rules. If you submit it there (and RW accepts it), it will be the first Jellyfish example in that thread.

by **Carcul** » Sun Nov 26, 2006 11:29 pm

Wapati wrote:JellyFish, my first one that is not trivial to avoid. There are two,
on the same digit but I doubt you can find both. Lots of finned-swords,
if you care to look.

Code: Select all: *-------------------------------------------------------------------* | 19 1389 2 | 5 38 7 | 6 1348 348 | | 67 4 38 | 1368 12368 1238 | 39 5 3789 | | 67 138 5 | 9 368 4 | 2 138 378 | |--------------------+----------------------+-----------------------| | 8 7 9 | 36 3456 35 | 1 34 2 | | 12 5 6 | 138 123489 1238 | 349 7 3489 | | 3 12 4 | 178 12789 128 | 5 89 6 | |--------------------+----------------------+-----------------------| | 25 23 7 | 4 135 9 | 8 6 135 | | 459 6 38 | 1378 13578 1358 | 349 2 13459 | | 459 389 1 | 2 358 6 | 7 349 3459 | *-------------------------------------------------------------------*

[r8c3]=3=[r2c3]-3-[r2c456]=3=[r13c5]-3-[r79c5]=3=[r8c456]-3-[r8c3],
=> r2c7/r2c9/r4c5/r5c5/r8c7/r8c9<>3 solving the puzzle.

Carcul

by **tarek** » Mon Nov 27, 2006 2:43 pm

These puzzles provide "straight down to business" tough puzzles....
#3 & #4 should be tougher, Enjoy......

Code: Select all: Toughie #01 . . 5 | 7 . . | . 3 . 3 . . | . 6 . | . . 4 . 1 . | . . 8 | . . . -------+-------+------ . 9 . | . . . | 5 . . . . 6 | . . . | . 1 . 4 . . | . . . | . . 8 -------+-------+------ 8 . . | . 4 . | . . 6 . . . | . . 6 | 2 . . . . 7 | 1 . . | . 9 . Toughie #02 9 . . | . . 3 | . . 1 . 8 . | . 4 . | . . . . . 2 | 6 . . | 9 . . -------+-------+------ 1 . . | . . . | . . 2 . 3 . | . . . | . 4 . . . 5 | . . . | 7 . . -------+-------+------ . . 7 | 5 . . | 6 . . . . . | . 8 . | . 3 . 4 . . | . . 1 | . . 9 Toughie #03 9 . . | . . 5 | . . 8 . 4 . | . 3 . | . . . . . 6 | 1 . . | 2 . . -------+-------+------ 8 . . | . . . | . . 6 . 5 . | . . . | . 3 . . . 2 | . . . | 1 . . -------+-------+------ . . 1 | 2 . . | 7 . . . . . | . 4 . | . 5 . 3 . . | . . 8 | . . 9 Toughie #04 5 . . | . 6 . | . 2 . . . 7 | 1 . . | . . 8 . 9 . | . . 3 | . . . -------+-------+------ . 2 . | . . . | 7 . . . . 8 | . . . | . . 1 6 . . | . . . | . 3 . -------+-------+------ 3 . . | . 2 . | . 5 . . . . | . . 9 | 6 . . . . 1 | 8 . . | . . 4

tarek

by **wapati** » Tue Nov 28, 2006 1:42 am

Ocean wrote:
This puzzle should also qualify as an "Effortless Extreme" - as far as I can read the rules. If you submit it there (and RW accepts it), it will be the first Jellyfish example in that thread.

Thanks Ocean, I will submit it.

I agree with "as far as I can read the rules".

by **re'born** » Tue Nov 28, 2006 1:06 pm

wapati wrote:JellyFish, my first one that is not trivial to avoid. There are two,
on the same digit but I doubt you can find both.

After filling in the first couple of singles, write down the Arcilla row matrix for 3:

R_3: [(2589), (345679), (2589)],[(4569),(45679),(1)],[(259), (345679), (2589)]

The naked quad is easy to find and implies that there is a Jellyfish in r1379c2589. To find the dual jellyfish, one can note the hidden quad in the above matrix (look at the 3,4,6,7) or, alternatively, write down the Arcilla column matrix

C_3: [(6), (1379), (28)],[(2458), (12345789), (2458)], [(258), (1349), (1235789)]

Thus the dual jellyfish is in r2458c3467.

Piece of cake!

by **Carcul** » Tue Nov 28, 2006 3:15 pm

Tarek wrote:These puzzles provide "straight down to business" tough puzzles....

Toughie 1:

Code: Select all: *----------------------------------------------------------------------* | 269 2468 5 | 7 129 1249 | 1689 3 129 | | 3 278 289 | 259 6 1259 | 1789 2578 4 | | 2679 1 249 | 23459 2359 8 | 679 2567 2579 | |----------------------+------------------------+----------------------| | 127 9 1238 | 23468 12378 12347 | 5 2467 237 | | 257 23578 6 | 234589 235789 234579 | 3479 1 2379 | | 4 2357 123 | 23569 123579 123579 | 3679 267 8 | |----------------------+------------------------+----------------------| | 8 235 1239 | 2359 4 23579 | 137 57 6 | | 159 345 1349 | 3589 35789 6 | 2 48 1357 | | 256 23456 7 | 1 2358 235 | 48 9 35 | *----------------------------------------------------------------------*

1. [r4c6]-4-[r4c8]=4=[r8c8]-4-[r8c3]=4=[r3c3]-4-[r3c4]=4=[r1c6]-4-
-[r4c6], => r4c6<>4.

2. [r4c3]=8=[r4c5]-8-[r9c5]=8=[r9c7]-8-[r1c7]=8=[r1c2]-8-[r5c2]=8=
=[r4c3], => r4c3=8.

3. [r5c4]=8=[r8c4]-8-[r8c8]-4-[r4c8]=4=[r4c4]-4-[r5c4], => r5c4<>4.

4. [r8c2]-4-[r1c2]=4=[r1c6]-4-[r5c6]=4=[r5c7]-4-[r9c7]=4=[r9c2]-4-
-[r8c2], => r8c2<>4 solving the puzzle.

Carcul

by **Carcul** » Tue Nov 28, 2006 6:52 pm

Toughie 2:

Code: Select all: *-----------------------------------------------------------------------* | 9 4567 46 | 278 257 3 | 2458 25678 1 | | 3567 8 136 | 1279 4 2579 | 235 2567 3567 | | 357 1457 2 | 6 157 578 | 9 578 34578 | |----------------------+------------------------+-----------------------| | 1 4679 4689 | 34789 35679 456789 | 358 5689 2 | | 2678 3 689 | 12789 125679 256789 | 158 4 568 | | 268 2469 5 | 123489 12369 24689 | 7 1689 368 | |----------------------+------------------------+-----------------------| | 38 129 7 | 5 239 249 | 6 128 48 | | 256 12569 169 | 2479 8 24679 | 1245 3 457 | | 4 256 38 | 237 2367 1 | 258 2578 9 | *-----------------------------------------------------------------------*

1. [r3c9]=4=[r3c2]=1=[r2c3]=3=[r9c3]=8=[r7c1]-8-[r7c9]-4-[r3c9], => r3c2<>5,7; r2c3<>6; r7c8<>8; r8c9<>4.

2. [r3c9]=3=[r3c1]-3-[r2c3]-1-[r3c2]-4-[r3c9], => r3c9<>4.

3. r4c5=6 or r8c2=6, and so r4c2<>6 solving the puzzle.

Carcul

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