The New Sudoku Players' Forum

by **wapati** » Fri Oct 20, 2006 6:13 am

RW, windows is safe on the Internet.

This puzzle is about ludicrous, I don't use that word often.

Code: Select all: 4.....3.. 78.....6. .91...2.8 84.5.2... ...6..... ..7.84... 1..2..7.. .6...895. ..8..9.42

by **ravel** » Fri Oct 20, 2006 7:56 am

wapati wrote:RW, windows is safe on the Internet.

LOL, you should say this on a hackers site.
My former boss used to ask "when will you finally learn to write bug free programs ?"

Nice puzzle.
[Added solution:]

Code: Select all: 4 25 256 | 8 125679 1567 | 3 19 159 7 8 235 | 139 12359 135 | 4 6 159 356 9 1 | 4 356 356 | 2 7 8 -------------------------------------------------------- 8 4 36 | 5 139 2 | 16 139 7 359 1235 235 | 6 1379 137 | 8 1239 4 369 123 7 | 139 8 4 | 5 1239 169 -------------------------------------------------------- 1 35 9 | 2 4 56 | 7 8 36 2 6 4 | 7 13 8 | 9 5 13 35 7 8 | 13 56 9 | 16 4 2

r6c9=6 => r7c9=3 => r8c9=1 (=> r8c5=3) => r9c7=6 => r9c5=5 => r3c5=6 => r3c1<>6 => r6c1=6

by RW » Fri Oct 20, 2006 9:25 am

wapati wrote:RW, windows is safe on the Internet.

Great! I'll uninstall all unnecessary internet security programs and virus protection software immediately!

wapati wrote:This puzzle is about ludicrous, I don't use that word often.

That one seems to "require" more if you restrict yourself to pattern based techniques up to XYZ. Couldn't find anything shorter than colors + XYZ + multicolors.

RW

by **ravel** » Fri Oct 20, 2006 10:59 am

RW wrote:Couldn't find anything shorter than colors + XYZ + multicolors.

Code: Select all: 4 25 256 | 8 125679 1567 | 3 19 159 7 8 235 | 139 12359 135 | 4 6 159 356 9 1 | 4 #356 356 | 2 7 8 ---------------------------------------------------- 8 4 36 | 5 139 2 | 16 139 7 359 1235 235 | 6 1379 137 | 8 1239 4 369 123 7 | 139 8 4 | 5 1239 169 ---------------------------------------------------- 1 35 9 | 2 4 56 | 7 8 36 2 6 4 | 7 #13 8 | 9 5 13 @35 7 8 |@13 -56 9 | 16 4 2

After eliminating 6 from r3c5 with coloring (3 strong links r3c1=r6c1-r6c9=r7c9-r9c7=r9c5) there is also a simple ALS (APE?):
A={135} in r38c5, B={135} in r9c14, x=1, z=5,
which eliminates 5 from r9c5 and solves the puzzle.

by **wapati** » Sat Oct 21, 2006 4:03 am

I am not sure if this takes more than three.

I need UR and BUG1 and at least one more "lower" method.

Code: Select all: 4..8..9.. .8......7 ....23.5. 2..6...35 ..6.5.7.2 ..7.....4 7...1.3.. ..95..... .6.789...

by **Ocean** » Sat Oct 21, 2006 8:06 am

The naked train:

Code: Select all: *-----------* |...|1.8|...| |.7.|.3.|.5.| |...|9.2|...| |---+---+---| |..1|...|2..| |.3.|...|.4.| |5..|.6.|..7| |---+---+---| |7..|...|..4| |.6.|.4.|.3.| |..2|...|8..| *-----------*

Simple Sudoku - the non-single moves: Naked Pairs; Naked Pairs; LC; Naked Quads (=Hidden Triple); LC; Naked Pairs; Naked Pairs; Naked Triples; Multiple Colors; No hints available (Bypass: Unique Rectangle); Hidden Pairs; Naked Pairs; Naked Pairs; Multiple Colors; Swordfish; LC; LC; LC; Colors (=Turbot Fish); LC; XY-wing.

Any shortcuts?

by **Carcul** » Sat Oct 21, 2006 2:26 pm

Wapati wrote:I am not sure if this takes more than three.(...) I need UR and BUG1 and at least one more "lower" method.

Code: Select all: *------------------------------------------------------* | 4 25 25 | 8 67 17 | 9 16 3 | | 69 8 3 | 149 46 5 | 1246 1246 7 | | 69 7 1 | 49 2 3 | 468 5 68 | |------------------+------------------+----------------| | 2 9 48 | 6 47 1478 | 18 3 5 | | 18 134 6 | 134 5 148 | 7 9 2 | | 5 13 7 | 123 9 128 | 168 168 4 | |------------------+------------------+----------------| | 7 245 2458 | 24 1 246 | 3 2468 9 | | 18 124 9 | 5 3 246 | 2468 7 68 | | 3 6 24 | 7 8 9 | 5 24 1 | *------------------------------------------------------*

Two step solution:

1. [r1c6]-1-[r2c4]=1=[r8c2]=4|8=[r6c7]=6=[r6c8]-6-[r1c8]-1-[r1c6], => r1c6<>1.

2. [r8c2]=4|8=[r6c7]-8-[r6c8]=8=[r7c8]-8-[r7c23]-4-[r7c4]-2-[r6c4]-3-
-[r6c2]-1-[r8c2], => r8c2<>1.

One step solution:

[r8c1]-8-[r7c23](-4-[r7c4]-2-[r6c4])-4-[r8c2]=4|8=[r6c7]=6=[r6c8]-6-
-[r1c8]-1-[r1c6]=1=[r2c4]-1-[r6c4]-3-[r6c2]-1-[r5c1]-8-[r8c1], => r8c1<>8.

Carcul

by **tarek** » Sat Oct 21, 2006 2:30 pm

Ocean wrote:Any shortcuts?

Not from me.........You're solution is shorter than mine which required some ALS steps.........

The shortcut would be some forcing chains/NICE loops following the UR reduction......I can't see it here

tarek

by **wapati** » Sun Oct 22, 2006 2:34 am

This one takes an x, xy, xyz and Turbot/ER, for me.

There is a UR but I think it only replaces one step.

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

by **wapati** » Sun Oct 22, 2006 3:54 am

I will (perhaps) solve this Monday.

It is the weekend, I am busy, I generated this monster.

I'll try it when I have time....

(It does look busy.)

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

by **wapati** » Sun Oct 22, 2006 5:27 am

Still on auto-pilot. Generating, not solving.

This is at least three for me.

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

by **ravel** » Sun Oct 22, 2006 10:49 am

Ocean wrote:The naked train:
Code: Select all
*-----------* |...|1.8|...| |.7.|.3.|.5.| |...|9.2|...| |---+---+---| |..1|...|2..| |.3.|...|.4.| |5..|.6.|..7| |---+---+---| |7..|...|..4| |.6.|.4.|.3.| |..2|...|8..| *-----------*

Simple Sudoku - the non-single moves: Naked Pairs; Naked Pairs; LC; Naked Quads (=Hidden Triple); LC; Naked Pairs; Naked Pairs; Naked Triples; Multiple Colors; No hints available (Bypass: Unique Rectangle); Hidden Pairs; Naked Pairs; Naked Pairs; Multiple Colors; Swordfish; LC; LC; LC; Colors (=Turbot Fish); LC; XY-wing.

Any shortcuts?

Very interesting puzzle, Ocean. Maybe the hardest i have seen, which can be solved with basics + coloring, UR, swordfish and xy-wing. I only saw one redundant step (the last turbot fish), but (leaving out the tuples) the following remains:
UR4, 3 strong links, 2 SL (turbot fish or ER), swordfish, xy-wing

by **wapati** » Sun Oct 22, 2006 8:52 pm

Ocean wrote:The naked train:

Any shortcuts?

Cool puzzle, no cuts from me!

by **wapati** » Sun Oct 22, 2006 10:20 pm

DAJ, I was teasing.

by **wapati** » Sun Oct 22, 2006 10:54 pm

Puzzle that takes me three patterns.

Chain gangs... I have no guess.

Code: Select all: ...5.76.. ...89.34. ..2..6..1 98.1..... .4...28.. 7.3.5.... 27..1.5.. .1.....67 ..6....2.

The New Sudoku Players' Forum

Fun puzzle. So many methods to solve. No CHAINS required.