## Low-Stepper STD-27

Everything about Sudoku that doesn't fit in one of the other sections

### Low-Stepper STD-27

The Guiness World Records contains a sudoku record (see about such a record event http://sudokucup.com/node/754). A candidate puzzle for this records must fullfill the STD-27 convention, i. e.

a) A grid with 9x9 cells and with bolded 3x3 boxes.
b) In the grid there are given 27 single digits (one third of the whole number) from 1 to 9, each of them is there three times.
c) In each row, column and bolded 3x3 boxes there are exactly 3 single digits.
d) The arrangement of the digits must assure solubility directly and logically and there must be exactly one correct solution.

The purpose of this thread is to collect lowstepper puzzles with STD-27 rules.

The steps are counted as in the inferior thread, i. e.

1. locate singles (naked or hidden) - but don't place any numbers
2. place all located singles in one sweep
3. count and repeat until solved

The puzzles are grouped by the following symmetry types:

* Type I = Full dihedral symmetry [F]
* Type II = Full rotational symmetry [L]
* Type III = Horizontal and vertical reflection [P]
* Type IV = Diagonal and anti-diagonal reflection [X]
* Type V = 180-degree rotational symmetry [R]
* Type VI = Horizontal or vertical reflection [H]
* Type VII = Diagonal or anti-diagonal reflection [D]
* Type 0 = No symmetry [A]

I hope for good and easy puzzles for STD-27.

Pyrrhon
Pyrrho

Posts: 3
Joined: 10 December 2010

### Re: Low-Stepper STD-27

Pyrrho wrote:I hope for good and easy puzzles for STD-27.

The conditions do not include minimality, so are the first two of these what you're looking for (the others are too hard)?
Code: Select all
` 1 . . 2 . . 3 . . . 3 . . 4 . . 1 . . . 5 . . 6 . . 7 8 . . . . 7 2 . . . 9 . . 6 . . 8 . . . 4 3 . . . . 5 6 . . 9 . . 4 . . . 7 . . 8 . . 5 . . . 2 . . 1 . . 9   ED=1.2/1.2/1.2 1 . . 2 . . 3 . . . 4 . . 1 . . 5 . . . 2 . . 4 . . 6 7 . . . . 3 8 . . . 8 . . 5 . . 6 . . . 6 7 . . . . 4 3 . . 5 . . 9 . . . 9 . . 8 . . 2 . . . 7 . . 9 . . 1   ED=2.0/1.2/1.2 1 . . 2 . . 3 . . . 3 . . 4 . . 1 . . . 2 . . 5 . . 6 7 . . . . 6 8 . . . 5 . . 9 . . 7 . . . 9 8 . . . . 4 9 . . 7 . . 1 . . . 8 . . 6 . . 5 . . . 4 . . 3 . . 2   ED=4.2/1.2/1.2 1 . . 2 . . 3 . . . 3 . . 4 . . 2 . . . 5 . . 1 . . 6 4 . . . . 5 7 . . . 6 . . 7 . . 8 . . . 8 3 . . . . 9 9 . . 7 . . 8 . . . 1 . . 9 . . 5 . . . 2 . . 6 . . 4   ED=7.1/1.2/1.2 1 . . 2 . . 3 . . . 4 . . 5 . . 6 . . . 5 . . 7 . . 4 8 . . . . 6 2 . . . 2 . . 3 . . 9 . . . 6 4 . . . . 8 7 . . 9 . . 8 . . . 5 . . 1 . . 7 . . . 9 . . 3 . . 1   ED=8.3/3.8/3.8`

Regards,

Mike Metcalf

m_b_metcalf
2017 Supporter

Posts: 9036
Joined: 15 May 2006
Location: Berlin

### Re: Low-Stepper STD-27

Code: Select all
`100200300030040010005006007800007200090060080004300005400900600070080050002001009    ED=1.2/1.2/1.2100200300030040010005006007800007200090060080004500003600900400070080050002001009    ED=2.0/1.2/1.2100200300030040010005006007800007200090060080003400005600900400070080050002001009    ED=1.5/1.2/1.2100200300030040010005006007800007200090060080004300005600900400050080070002001009    ED=1.2/1.2/1.2100200300030040010005006007800007200050060080004300005600900400090080070002001009    ED=1.2/1.2/1.2100200300040050060003001002500007800070090020001800006700900400090040080006005003    ED=2.0/1.2/1.2100200300030040010005001006700006200080090070004300005900800400060070050002009008    ED=2.0/1.2/1.2100200300030040010005006007800007200090060080004300005600900400020080050007001009    ED=1.2/1.2/1.2100200300040030020005006004700008400090060070008100009800600200050070030009001005    ED=2.0/1.2/1.2100200300040050020006007008200004500050070090009600004600300800010080030007009001    ED=2.0/1.2/1.2100200300030040010005006007800007200090060080004300005600900400070080050009001002    ED=1.5/1.2/1.2100200300030040010005006007800001200090060080004300005600900400070080050009007002    ED=2.0/1.2/1.2100200300030040010005006007400001200080060090009300005600800400070090050008007002    ED=1.5/1.2/1.2`

m_b_metcalf
2017 Supporter

Posts: 9036
Joined: 15 May 2006
Location: Berlin

### Re: Low-Stepper STD-27

Thank you. Yes this I have in mind. With respect to multiple kinds of reflection in the same puzzle the records are now

in type V and 0:

6 stepper

53.....2...24....7....31.4.4....78....6.5.9....96....1.7.81....6....35...9.....82 (Robert Babilon)

8 stepper

1..2..3...3..4..1...5..6..78....72...9..6..8...43....56..9..4...5..8..7...2..1..9 (m_b_metcalf)
1..2..3...4..5..6...3..1..25....78...7..9..2...18....67..9..4...9..4..8...6..5..3 (m_b_metcalf)

9 stepper

1..2..3...3..4..1...5..6..78....72...9..6..8...34....56..9..4...7..8..5...2..1..9 (m_b_metcalf)

and in type IV and VII:

8 stepper

1..2..3...3..4..1...5..6..78....72...9..6..8...43....56..9..4...5..8..7...2..1..9 (m_b_metcalf)
1..2..3...4..5..6...3..1..25....78...7..9..2...18....67..9..4...9..4..8...6..5..3 (m_b_metcalf)

9 stepper

1..2..3...3..4..1...5..6..78....72...9..6..8...34....56..9..4...7..8..5...2..1..9 (m_b_metcalf)

10 stepper

1..2..3...3..4..1...5..6..78....72...9..6..8...43....56..9..4...7..8..5...2..1..9 (m_b_metcalf)
1..2..3...3..4..1...5..6..78....72...9..6..8...43....54..9..6...7..8..5...2..1..9 (m_b_metcalf)
1..2..3...3..4..1...5..6..78....72...5..6..8...43....56..9..4...9..8..7...2..1..9 (m_b_metcalf)
1..2..3...3..4..1...5..6..78....72...9..6..8...43....56..9..4...7..8..5...9..1..2 (m_b_metcalf)

Pyrrhon
Pyrrho

Posts: 3
Joined: 10 December 2010

### Re: Low-Stepper STD-27

Well, here are some more. These aren't difficult to produce, but I don't really see the point.

Code: Select all
`120000030004500006000037010700005600008090100009200003050670000800004200090000048    2.6/1.2/1.2120000030003400005000026040400001700008050900009800006050760000800002100090000073    1.2/1.2/1.2120000030003400005000026040500004700008010900009800006050760000800002100090000073    1.2/1.2/1.2120000030003400005000026040400005700008010900009800006090760000800002100050000073    1.2/1.2/1.2120000030003400005000026040400005700008010900009600008050760000800002100090000073    1.2/1.2/1.2120000030004500006000021050500006700003010800008300009060790000800004200090000074    1.2/1.2/1.2120000030003400005000026040300005700008010900009800006050760000800002100090000074    1.2/1.2/1.2120000030003400005000026040300005700008010900009800006090760000800002100050000074    1.2/1.2/1.2120000030003400005000026040400005700008060900009800001050710000800002600090000073    1.2/1.2/1.2120000030003400005000026040400007800009010700005900006070860000900002100050000083    1.2/1.2/1.2120000030004300005000064070200003700005080900008100006090420000700008500010000069    2.0/1.2/1.2120000030004500006000017020500003400006040800007800002070930000800006900090000015    1.5/1.2/1.2120000030003400005000026040700004800009010700005900006050860000900002100070000083    1.2/1.2/1.2120000030004300005000046070800002300009080500006900001060570000700008400010000029    1.2/1.2/1.2120000030003400005000026040400005700008010900009800006070560000800002100090000073    1.2/1.2/1.2120000030003400005000026040400005700008010200009800006050760000800009100090000073    1.2/1.2/1.2120000030003100004000025060600004700008010900009800005040750000800002600090000073    2.0/1.2/1.2120000030003100004000025060600004700008010900009800005080750000400002600090000073    2.0/1.2/1.2`

Regards,

Mike Metcalf

m_b_metcalf
2017 Supporter

Posts: 9036
Joined: 15 May 2006
Location: Berlin