The New Sudoku Players' Forum

[JPF]

19-clues house

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JPF

[Mauricio]

Minimal shuriken.

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 . . . . . . 7 . .     ER 8.4


[JPF]

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JPF

[JPF]

19 clues, parallel-diagonal symmetry

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JPF

[wintder]

That is 8 X 8 symmetry.

It isn't 9 X 9.

[JPF]

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That is 8 X 8 symmetry.
It isn't 9 X 9.

The line L = r1c2-r2c3-...-r7c8 = [1,2,5,2,3,2,9], parallel to the diagonal, is an axis of symmetry for the set of the non empty cells in the puzzle.

My point is :
Is there any valid puzzle such that the mirror cells have the same digit ?

We know that it is not possible for the classic reflections of a sudoku grid.

JPF

[Mauricio]

That is 8 X 8 symmetry.

It isn't 9 X 9.

Clever observation, and the point is?

I have created a list of 180 degrees symmetric 18's. There are almost 24K and no two of them are isomorphic. It is zipped here.
There are essentially 1036 different patterns in that list.

I have updated that list. Now it has a little over 60K puzzles. There are 1704 different patterns in that list, isomosphic patterns counted once. I found 2 new 17's minimalizing the sudokus of that list . Here are the 668 sudokus of that list that have double diagonal symmetry or are isomorphic to a sudoku with DDS. Then I did a similar search in that list for sudokus with horizontal and vertical symmetry or isomorphic to a sudoku with horizontal + vertical symmetry and found 0.

Here are the 1024 sudokus of that list that have a non trivial automorphism.

This could be the sudoku in that list with the highest SE rating

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. . . . . 5 . . 4     ER 9.2


[wintder]

That is 8 X 8 symmetry.

It isn't 9 X 9.

Clever observation, and the point is?

It is not a symmetric sudoku puzzle.

[wintder]

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That is 8 X 8 symmetry.
It isn't 9 X 9.

The line L = r1c2-r2c3-...-r7c8 = [1,2,5,2,3,2,9], parallel to the diagonal, is an axis of symmetry for the set of the non empty cells in the puzzle.

My point is :
Is there any valid puzzle such that the mirror cells have the same digit ?

We know that it is not possible for the classic reflections of a sudoku grid.

JPF

I don't follow you but if this is cool it is a whole new idea!

[JPF]

Sudoku's cup:

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nothing to do with brandy light

JPF

[JPF]

goddess Venus' hand mirror

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JPF

[ravel]

Nice again, i am awaiting more

[JPF]

Mars :

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ER=6.6

Jupiter :

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JPF

[Mike Barker]

JPF, I think your latest have been the best yet - recognizable and generally symmetrical. I've been keeping a list of my favorites. Claudia would it make sense to keep a list in the first post of those posted here and elsewhere? Here's my list in line format. Having the full grid might be better, but also long.

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.15...26.9..4.1..88...2...34.......62.......7.6.....5...9...1.....5.7.......9.... #valentines (ab)
.58...41.7..4.5..32...1...99...4...2.7.....3..6.....5...1...8.....2.7.......5.... #valentines (ab)
...........98.56...5.9.6.7..83...91...........61...84..7.1.4.6...86.95........... #shape#9 (ab)
..4...59..9...6..4.1..7.....3..89.....5.6.9.....34..1.....2..8.7..5...3..86...7.. #spiral (claudiarabia)
....327...5.6...1...47....8.2794....9..21....3....8...2.....3...6.....4...8.....1 #bird (claudiarabia)
.527.........3...1.....2..3..7.4...2.3.6.7.8.6...2.9..9..8.....1...6.........516. #spiral (foxglove)
..3...5...9.3.2.6.8...5...9.8.....9...1...8...6.....5.7...6...2.3.7.5.4...8...1.. #clover (Henk)
.........5.......4.1.....9..3.....1...9.3.2.....5.1....968.234.2..4.5..7......... #alien (JPF)
..5...8...6.....1..8.....7..3.....6..7.....9...29.54......6........1......93.42.. #brandy light (JPF)
12.....34.5.....1..6.....7..1.....5..8.....2...7...8.....816.......5......64.39.. #sudoku cup (JPF)
...4156....3....9..6......47.6.....54..352..83.....9.18......7..7....2....2937... #ying-yang (JPF)
6.......3...861.....4...7...1.7...5..6..9..4..9...4.6...7...1.....589...5.......9 #do not (JPF)
..8.......9.6.....4...1.......7.5.....4...1...3...9.5.2...8...9.5.9...7...7...4.. #catamaran (JPF)
........5..17...4..2..9.8...1...7.....3...2.....1...5...5.3..1..8...26..9........ #spinning top (JPF)
....987.....3...6...7.....5..4.....1...237...6.....3..3.....9...5...1.....258.... #snake (JPF)
.....123.....4...5....6...7.....817...........659.....1...3....3...7.....485..... #circles (JPF)
....1.......2.3.....4...5...3.....6.7...8...3.5.....2...2...4....1.4.9...8.....5. #house (JPF)
...123.....4...2...5.....6..7.....8...9...5.....479.......3......32649......8.... #Venus (JPF)
...123.....4...2...5.....6..7.....8...9...5.....479.......3......32649......8.... #Mars (JPF)
..123..4..5...6.1......4.7.....8..9....7...6...4....3..2.....8.765813429.......5. #Jupiter (JPF)
...163.....4...9...7.....1.6.......59..5.7..48.......9.3.....7...8...2.....892... #shape#1 (JPF)
....7......5...9...3.5.4.2...3.4.1..4..3.1..9..1.5.8...8.7.2.5...9...6......1.... #shape#2 (JPF)
...3.2.....26.17...7.....4.93.....54....8....68.....39.9.....1...85.46.....1.7... #shape#3 (JPF)
6..319..7...2.4............18.....697...6...124.....75............4.8...9..753..6 #shape#4 (JPF)
..1.......2....34..35.426.1..67.8.....3...9.....2.64..9.836.25..64....3.......7.. #spiral/shuriken (Mauricio)
1.......23...4...5...6.5...7.......4...871....8.....2...3.5.7....13.98........... #UFO (Ocean)
..6...5...7..3..9.4.......61.......2.2.....3...4.5.6.....1.7....8..9..7....4.5... #flower (Ocean)
8.5...4.6.9.....7.6.1...8.9...815.......6.......243...9.4...1.8.3.....5.5.8...3.7 #shape#5 (Ocean)
....8......4...3...5.2.6.9...3.6....8..7.1..9....5.4...2.1.9.7...5...6......7.... #shape#6 (Ocean)
9.....54221....9....4.....8...841.......2.......376...4.....8....7....13628.....7 #shape#7 (Ocean)
..........1.....2...34.56....4.5.3.....2.7.....6.8.4....56.31...7.....9.......... #shape#8 (Ocean)
....1........5....8...9...6.1..3..4...7.2.9.....467...491685273...3.1.....5...8.. #alien (ravel)
....2....6...7...3.1..4..8..9..8..2...7.9.5.....154....815.734.2..8.9..6..6...8.. #alien (ravel)
..59....8..1.....5..23........4...1...7.3.2...6...1........94..9.....7..8....53.. #Ys (Ruud)
....3.....4..7..1...85.12....3...4..79.....81..1...9....93.85...2..4..6.....5.... #medal (Ronk)
12395....9.4......765......3..6.....5...9...8.....3..7......154......7.2....27869 #arrows (RW)
572..4...4.1......693.........189..7...3.7...3..425.........782......6.5...2..431 #boxes (RW)
.........4........2.574391.5.8....6.1.9.78.3.3.2..6.7.9.3285.4.8......9.72649158. #snake (tso)
...981.....4...7...6.....8.6...3...53..8.6..91...2...7.9.....4...2...5.....475... #circle (tso)
....54683.....9..1......2.9.......788.......569.......5.6......2..8.....34756.... #triangles (tso)
.6.3.8.1..........2...7...4..6...2..1.......7..8...5..4...1...2..........1.4.3.6. #sparse (tso)
...4985....3....2..1..32..9.5.3..6.8.3....2.7..2..4..32..58..7..6....8....8213... #spiral (tso)
.983.....5...6....2...7....7.........316.829.........4....1...6....4...5.....574. #figure8 (unknown)
.389..4..9...4.5..4...6..938...3.....435.926.....2...578..9...4..6.7...2..4..675. #circles (unknown)
1.......2.3..4..5....6.7.....6...7...4..7..8...8...9.....9.4....2..8..1.5.......3 #diamond (unknown)
...........1...2...2.1.3.4...5.6.7.....2.4.....6.5.8...1.3.7.9...8...5........... #big X (unknown)
1...7...6.2.....4...3...8.....4.2...6...5...1...8.6.....8...4...3.....2.7...9...5 #X (unknown)
6.......3.5..1..4...8...9.....3.6....4..2..5....9.4.....9...3...1..7..2.8.......6 #X (unknown)
6.45.27.9.........9..7.8..28.32.41.7.........7.91.52.83..4.1..6.........2.79.38.4 #boxes (vidarino)
56.....248.......7..21.65....1.4.7.....317.....9.5.3....54.98..2.......697.....31 #gunsight (Vidarino)

6...1.......625.......3...7..29438......5.....9186742.....7....749582163...194... #Xmastree and 2 snowflakes

(m_b_metcalf) SE8.3
4...2.......548.......7...6..57839......6.....3791426.....3....123456789...892... #Xmastree and 2 snowflakes

(m_b_metcalf) SE4.5
....2.......8.7...397...825.3.....7...9.6.1...5.....8.172...956...9.5.......7.... #star (ab)
..........28..53169..8.2......7.645...4.....7.1......22....8..95362..87.......... #25 (JPF)
9...4...1.2..9..5...3.8.6.....7.5...152...793...3.9.....5.7.2...8..5..7.4...3...5 #star (m_b_metcalf) easy
5...3...1.8..2..6...2.9.3.....9.8...97.....52...2.1.....3.1.7...5..6..4.4...8...9 #star (m_b_metcalf) SE7.2
4...9...6.8..1..5...3...1.....4.7...7.2...4.3...8.6.....1...2...5..6..3.6...8...7 #star (m_b_metcalf) SE7.2
....6.......5.8...763...485.7.....4...9.2.6...3.....1.214...759...9.1.......7.... #star (m_b_metcalf)
....273.....5..64...1..3.5...9652.....6..4.....7..9......38.....83..19..6......7. #elf (m_b_metcalf)
93.7.1.867..6.5..9....8.......2.6.....7...1....8...6....5...2...1495287.....1.... #sleigh bell (m_b_metcalf)
....273.....5..64...1..3.5...9632.....6..4.....7..9......38.....83..69..6......2. #elf (RW)
81.4.2.932..5.8..1....1.......1.6.....9...1....6...4....5...2...7192563.....8.... #sleigh bell (squirrel)
32.9.5.149..1.4..2....2.......7.3.....4...1....8...7....2...8...1643257.....9.... #sleigh bell (squirrel)

I've tried to keep track of the links, but haven't been completely succesful.
http://forum.enjoysudoku.com/viewtopic.php?t=4147 - Sudokus with an original rare shape
http://forum.enjoysudoku.com/viewtopic.php?t=3585 - The SUPERIOR thread
http://forum.enjoysudoku.com/viewtopic.php?t=3609 - Inferior puzzles thread
http://forum.enjoysudoku.com/viewtopic.php?t=3721 - Fully symmetrical puzzles
http://forum.enjoysudoku.com/viewtopic.php?t=4201 - Non-adjacent clues
http://forum.enjoysudoku.com/viewtopic.php?t=1180 - Largest number of empty groups?
http://forum.enjoysudoku.com/viewtopic.php?t=5106 - Christmas is coming

[claudiarabia]

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My new personal bestmark SE 9,5 Never saw a rating with 33 Dynamic Contradiction Forcing Chains

Claudia