The New Sudoku Players' Forum

by **eleven** » Mon Jan 26, 2015 3:35 pm

dobrichev wrote:The number of 36s exeeded the number of grids, so most grids are expected to have a 36-given minimal puzzle.
Is this collection of 36s the largest systematic collection of sudoku puzzles ever done?

To my knowledge, yes. The biggest one i remember are the (unpublished) 1.2 billion 18 clues of ano1.

by **coloin** » Mon Jan 26, 2015 11:52 pm

Well it certainly is a lot of puzzles - and it explains why we found a 36 in a random grid a way back ......
How do you keep tabs on all of them - my isomorph sorter runs out of memory at under a million grids...... ?

This first found 36 puzzle is from the MC grid [most canonical]

Code: Select all: +---+---+---+ |..3|..6|78.| |..6|78.|12.| |78.|12.|45.| +---+---+---+ |.31|.64|8..| |.64|8..|2..| |8..|2..|5..| +---+---+---+ |312|645|...| |645|...|...| |...|...|...| +---+---+---+

Out of interest did you find a 37 in this grid ? !!!!

by **dobrichev** » Tue Jan 27, 2015 8:42 pm

coloin wrote:How do you keep tabs on all of them - my isomorph sorter runs out of memory at under a million grids...... ?

I explained the data model earlier in this thread. But let repeat it with some new details.

My generator uses as input a stream of subgrids with up to 40 givens (the seed). Then it strips them to 35 givens, sorts them in memory in minlex form, and adds givens. Any minimal puzzle of size 36+ is converted to minlex and added to a sorted list in memory.
The input size (batch size) is optimized to use the 64GB RAM. It is 70,000 puzzles for 37+ seed and takes about 4 hours and half to complete. For 36s the batch size is 10,000,000 puzzles and takes about 2 hours and half.
After all puzzles are processed, the sorted list is written to a file. A tag with number of givens is added at the end of each puzzle.
Then the puzzles from all batches for this generation are merged in a single ordered file.
Then the puzzles of size 37, 38, 39, 40 are filtered in a separate files, the known ones are removed by single pass over the known puzzles of the respective size. The file with all puzzles is kept for later extraction of 36s.
The new puzzles are checked for twins, and the minimal twins are added to the new puzzles of the respective size.
Then all new 37+ puzzles are used as a seed for the next generation.
New puzzles are added to the sorted list of known (and processed) puzzles with the respective size.
After the 37+ seed for the next generation is reduced to about 40,000 puzzles, the generated 36s are filtered, compared to the known 36s, checked for twins, and added to the seed. Comparing to the known 36s takes several hours. The known 36s are currently kept in 11 zipped files of sizes between 3 and 20 GB, each of them sorted. About 2/3 of the known 36s are "processed" (i.e. {-1+} is done). One or two files of known 36s are processed at once and after processing the files are renamed.
Recently a typical generation of 36+ puzzles consists of 60 batches and a 37+ generation starts from 8 batches gradually decreasing to a single batch.
Generation and filtering are automated, but adding the puzzles to the collections of knowns and processed puzzles is done manually, just for safety and for prevention of collections corruption. Manual work takes several minutes per generation when seeding with 37+ puzzles and almost one day for preparation and finalization of a generation with 36-givens seed.

For few times I also stripped out the 39s down to 34 givens and involved the so generated 36+ puzzles in the process.

coloin wrote:This first found 36 puzzle is from the MC grid [most canonical]

Interesting. I didn't know that.

coloin wrote:Out of interest did you find a 37 in this grid ? !!!!

After a run over the most of the 37s (those copied to my PC) I found no puzzle in MC grid.

by **dobrichev** » Tue Jan 27, 2015 8:49 pm

eleven wrote:The biggest one [collection] i remember are the (unpublished) 1.2 billion 18 clues of ano1.

I am open to publish 37s and 36s if there is interest. Most 38+ are already in public space.

by **dobrichev** » Tue Feb 24, 2015 8:56 pm

102 more 39s

Hidden Text: Show

Code: Select all: .............12.34123..4.56.617...8.27..68..338.12..675162.7.4873..81..58......7. ...........1..2.34.5634...7..8..64...6..58.735.71348.6.15.237.8.8..1...27.2.853.1 ...........1.23.45.24.651.3.1.23..67.37..6...2.6.87..4.72.5843.143.72.585......7. ...........1.23.45.2456.13...768..13.4.7..58.18..35.27.1237.854.7.2..3..4...5..7. ...........1.23.4524..1563......7..61.6258.7447.1.658..185.2..762..7185.7...8.... ...........1.23.4524..1563......7..61.6258.7447.1.658..285.1..761..7285.7...8.... ...........1.23.45264.5..31..7.8...4.8...2.17412.37.86.463...721...75.6.7.8..41.3 ...........1.23.45462.5..31..7.8...4.8...2.17214.37.86.463...721...75.6.7.8..41.3 ..........12.34.56.35.2614...7..281..58.7....12..48.75.7..6358..8.2...675.6.8..31 ........1..1..2.3.34.15..26..7....6..36.45.8748..7...3.1..24.787.45.8.1282.71.6.5 ........1..1.23.4..5..1426.....37.82...4..37.73..524.6.1624875..7...5...58..71624 ........1..1.23.4..5..1462.....37.82...4..37.73..524.6.1624875..7...5...58..71264 ........1..1.2345.245.167.3..4..8.....86.2.4552..3.8.7.83..157.1...8...44523.7..8 ........1..1.2345.452.16.73..5..8.....86.25.424..3..87.83..174.1...8...55243.7..8 ........1..2.13.4.14..25637.....84..48.35..7.7.5.64.83.6.....182.7.8136.81..367.. ........1..2.3456.35..162......4.71.5...784.674.6.1.2..15.8367..7......383..67152 .......12....1345...42.53......6..3..435.726.6.7.32584.31.2864..8...61..4.6.51.2.

Code: Select all: ...........1..2.34.23.541.6.....76.8.165.8.47.874.6315..8.7.....7..438.11.28.5.73 ...........1..2.34.23.5416......768..165.8.47.874.6351..8.7.....7..4381.1.28.5.73 ...........1.23.45.245..631...3.7..8.17.8.354.8..45.67..8....7..7283.5161.6..2.83 ........1....12.3..12.34.56.2..78..5.47.25.838..4.3.7..6..8.5..27...6.1858.241.67 ........1....2345.245.16.73.1..8...53.8..174.4523.7..8.24.3..875....8...8.16.25.4 ........1..1.2345.452.16.73....8...5.83..174.5243.7..8..5..8....186.25.424..3..87 ........1..2..3.4...1.452.6..7...8...38.74.1221...8.74.2..8..63.83.561277.63.14.8 ........1..2..3.4...1.452.6..7...8...83.74.1221...8.74.2..8..63.38.561277.63.14.8 ........1.12.34.5.56.1.2.43..6..7.8..57.286.482.4.6..5.7..814...8.2435.72..7....8 ........1.12.34.56.3561.24...7.......583.6.2732.78..65.73..8.1..814.35..5..17..8.

Code: Select all: ...........1..2.34..2.351....6..37.8.17.8..63.83.67415.28.4..5.1...568.26.5.28.41 ...........1.23.45243..5.16.371.2.681.63.8.5.4.8.671...728....43...7..8.8.4.36.7. ........1..2.13.4..1354..2...5.6.27..714....62.637.1.4.2.73...5.3785.4625.8..47.. ........1..2.34.5..561.243....7..8...45.83.17.784.13.5.2...8.7..87.165.256...718. ........1..2.34.5..561.243....7..8...45.83.17.874.13.5.2...8.7..78.165.256...718. ........1..2.34.56.536.142...61.75....7.6..145.1.48.67.3548..72.7.......2.87.3.45

Code: Select all: ...........1.23.45.2364.17..18.6.5...5..82.612.6.5..8..82...7..17..38..663527.81. ...........1.23.45.245.6.31..7....83.387.54.224..38.17.1...7..8.76..2154.82.5..7. ...........1.23.45.42.56731.....2.1..24.8.3.6.5863.42...7..8..4.85.6.17.41..75.83 ...........1.23.45236.457.1.2...1..81.3.8..6.6.83.21.4.672.48..3...78..68.2.3.4.7 ..........12.34.56.34.5612......7.18.2..8.7...78.612.5.4761.582.8..4.67.2...7..41 ........1..2.13.4..51674.32........8.85.3642727..486....7..1.8..18.65.7452..871.. ........1..2.13.4..51674.32........8.85.4632727..386....7..1.8..18.65.7352..871.. ........1..2.13.4.14...563...6.71.847.4.381.68..26.37...7..2..82.5.874.348..5.7.. ........1..2.1345..134..267...8......38.75.4227..34.85..7.8...4.2.5.1.7..81.47526 ........1..2.1345..134..267...8......78.35.4223..74.85..7.8...4.2.5.1.7..81.47526 ........1..2.1345..314..267...8......83.75.4227..34.85..7.8...4.18.47526.2.5.1.7. ........1..2.34.5..3.1.542......67...7631824.2.34.7.16.2.5.3.64.6574....3..6.157. ........1..2.3456.35.7.1.48..1.......271.3.8553..78.12.43..7.5626......47.54.6.23 ........1..2.3456.35.7.1.48..1.......271.3.8553..78.12.63..7.5424......67.54.6.23 ........1.12.34.5..3615.4.2..73....8.2..85..7.6847.52..73.48.15.81....7.2.571.8.. ........1.12.34.5..531.6.42..7..8....2.3.5.78.38.67.25.8.......2.1.835.4395.41.87 ........1.12.34.5..531.6.42..7..8....2.3.5.87.38.67.25.8.......2.1.835.4395.41.78 ........1.12.34.5..531.6.42..7..8....2.3.7.85.38.65.27.8.......2.1.835.4395.41.78 ........1.12.3456..561.274..318..6...68.731.55.7..1.8..75.4.8...84..7.566....84..

Code: Select all: .............12.34135....26..7.....3.13.754684563.8.71.6...7....74.5.6825218...47 .............12345.13..4267....7.5...38.45726.5.2.8.34.7.....1..81.2.4.334..81672 .............12345.13..4627....7.5...38.25764.5.4.8.32.7.....1..81.4.2.332..81476 .............12345.13..4627....7.5...38.45762.5.2.8.34.7.....1..81.2.4.334..81276 ...........1..2.34.3415.2....6.753.8.782...453.58..72..1762.453.6.....7.4.3.17.62 ...........1.23.45.24.163.7..7..8....18.75463.45.3.7.8.5..6.8..1.6..25.4482.5..36 ...........1.23.45.241.5.36..7.826.3..87...5.2.6531.78.85..7..441.....677.23..58. ...........1.23.45.241.5.36..7.826.3..87...5.2.6531.78.85..7..441..5..677.23...8. ...........1.23.45.245..63...3.57.6...683157...72.6.8..1..7.....7238541.43.1.275. ...........1.23.45.245.6.31..7....83.387.54.224..38.17.1...7..8.76.82154.82.5.... ...........1.23.45.2465.3.1..7..25..24..651.765..7...4.7..3...83.6.874.248.2.67.3 ...........1.23.45.425.6713........8.2.8.743.4.83.2.71..46...57.162.5384.5...816. ...........1.23.45245..1.36....37.6..371...2841.2.8.73.248....7.78.12.5415..7..8. ...........1.23456245.6137...7.......2.37..4545..82.37.14....8.5.2.38.1487..1.56. ..........12.34.56.345.62.1....47.85..36.87.2.87.526....58.3..7.78.6....3.1.75.68 ..........12.34.56.3526.41...7..3.8..2..4..71.5.72.634.71...86.28.37.1455...8...7 ..........12.34.56.356.2741.....3..8.8.24.57.52.8.7.14..84.61...5...8.67.6137..8. ..........12.34.56.3562.741..148.56..8...7..45...63..8..73.6.85..8.7..1..5384.6.7 ........1..1.23...24..15.36.26.478..7.4.5..6.8....2..7.8..761..1.7234..8462.81.73 ........1..2.13.4..145.623...7..8....26.5738..8.36.7.2.48..51...6143.8..5.3.8142. ........1..2.1345..134..267...8..7...78.35.4223..74.85..7.8...4.2.5.1....81.47526 ........1..2.1345..4125..3...6.......24.76.8387..32.64.1..658.2.5...1.46.6872..15 ........1..2.1345..4125..3...6.......74.62.8582..75.64.1..368.2.3...1.46.6872..13 ........1..2.34.5..631.5.24.....7...3865.2.177..3.1.82..87..2..2.7453..8634..8.75 ........1.12.34.5..56.1243...42......21.735..5.74.13....83.6.75.65.47.83.7...864. ........1.12.34567.5316.248....1...2..1..865.28.6.3.14.2...6.75.387..42.5.7.4.... ........1.12.34567.5316.428....1...2..1..865.28.6.31.4.2...67.5.387..24.5.7.4.... ........1.23.14.565.1276.43....21468....6..1....4.85.7.7.....8.2...87.343.8642.75 ........1.23.14.565.1672.43....21468....6..1....4.85.7.7.....8.2...87.343.8246.75

Code: Select all: .............12.34.356...12..7126.85.5.4.8.71.8.75.42...827.143.138....77.4....58 .............12.34123.45.67..1....86.38.5671.76..8134..82.7....3..5.4..85.4.28.73 .............12.34123.45.67..2....863.8.5672.67..2834..3.5.4..8.54.81.738.1.7.... .............12345.13..4627....7..5..38.25476.5.4.82.3.7....1...81.4..6262..81734 .............12345.13..4627....7..5..38.45276.5.2.84.3.7....1...81.2..6464..81732 .............12345.13..4627....7.5...38.25764.5.4.8.32.7.....1..81.4.2.662..81473 .............12345.13..4627....7.5...38.45762.5.2.8.34.7.....1..81.2.4.664..81273 ...........1..2.34.23.45..1.462.7.15312.54.765...6.4...68......1.4.28.6.235.761.8 ...........1..2.34.23.54..1.462.7.15312.45.765...6.4...68......1.4.28.6.235.761.8 ...........1..2.34.53164.27...6...83.3684.7.2.87.2546...8.5.....1.4...75.7521.348 ...........1.23.45.23.451.6.1..78.63.68.327.13.7.6..8..86..7..41...84..77.425...8 ...........1.23.45.23.451.6.1..78.63.86.327.13.7.6..8..68..7..41...84..77.425...8 ...........1.23.45.24.15.36..2....78.76.384..4.8.72361.1.3.7.84.47.81..38...5..1. ...........1.23.45.245.6.13..7....38.387.512.21..38.74.4...7.8..76..2451182.....7 ...........1.23.45.245.6.13..7....38.387.542.24..38.71.1...7.8..76..2154482.....7 ..........12.34.56.3562.741..148.56..8...7..45...63.78..73.6.85..8.7..1..5384.6.. ........1....2345..24.163.7.45..8...2.8.6.57.67.2.58.4.57..21.8462.8173.8......4. ........1..1..234..35.41672.....4....586.7.344.3.5..67.1.....2.3.2.1578658.2.6.13 ........1..1.23...24..15.36.26.478..7.4.5..6.8....2..7.8..761..1.72346.84.2.81.73 ........1..2.13.45.14.5236......7....87.2..3424..3..17.7826..534.6.75.8.52...8.76 ........1..2.13.45.4125..3...67...8..28.36.744.78.5.63.64.7.3..2......577.53.241.

2 x 40
2 424 x 39
2 014 078 x 38
337 246 430 x 37

by **dobrichev** » Sat Apr 25, 2015 4:56 am

144 more 39s in order of their discovery

Hidden Text: Show

Code: Select all: ...........1..2.34.53164.27...6...8..3684.7.2.8732546...8.5.....1.4...75.7521.348 ...........1.23456.42.15.37........82...6834.8.43.26.5..8...7..1.6.37.844.7.81563 ...........1.23456.42.15.37........82...6854.8.45.26.3..8...7..1.6.57.844.7.81365 ...........1.23456.42.15.73.......8.2...685.48.45.263...8...7..1.6.57.484.7.81365 ...........1.23456.42.567.1..........2856.31441..826.5.3..4..68.8.6.51.31...385.7 ...........1.23456.45.1672...........186.234545..8126..3...4.82.8.26.53.5...3867. ........1..1..234..35.41672.....4....586.7.344.3.8..67.1.....2.3.2.1875658.2.6.13 ........1..2.13.45.4125..3...67...8..28.36.744.78.5.63.6457.3..2.......77.53.241. ........1.12.34.5..631.542...7.5..8..8...37.22368.7.45.28..1....513.82.43..5...18

Code: Select all: .............12.341345...26.278.1.4534125..875.8.7.....731...684....8.7.8..72.4.3 ...........1.23.45.2..41.63..713...82...78.5.81..52.37.72..5..418..94.7.34..1758. ...........1.23456.42.5671...5.8..6..2...518..38612.7..13..8....84.67.3126..3.84. ..........12.34.56.34.561.2....78....485...73.7.4238.5.25..7..8.87.4.5.14.1.8..27 ..........12.34.56.35.6214.....78....286...37.7.25386..56..7.8..87.2.61.2.1.8..75 ........1..1..2.3..42.135.6.....7.6..87.36.454.6.587.3..4.8...7.1.7..352.75321.84 ........1..2..345..4.12.36...47.213.32.68174.7..3......7...65..2.65.78..45.21867.

Code: Select all: ...........1..2.34.3514672...7.8.....18.27..6.436.187..54.1826..8.2.54..1...6458. ...........1.23.45.23.45.61..7.8..5..1..36.87.84.721.6.46..75.8.7..5461.1....8.74 ...........1.23.45.456..273.....7..8.87..64214.62.8.57.3.1..58..5.3.2.141.48...32 ...........1.23.45.456..273.....8..7.86..74214.72.6.58.3.1..58..5.3.2.141.48...32 ...........1.23.45.456..273.....8..7.87..64214.62.7.58.3.1..58..5.3.2.141.48...32 ...........1.23456.457..823....8.....68.7.3144.736.58..2.1..6.5.5.23.14.1.46..23. ...........1.23456.457..823....8..6..68.7.3144.736.58..2.1....5.5.23.14.1.46..23. ..........12.34.56.34.561.2....78....485...73.7.4238.5.25..7..8.87.4...14.1.85.27 ..........12.34.56.34.561.2..3.78....485...73.7.42.8.5.25..7..8.87.4...14.1.85.27 ..........12.34.56.34.561.2..3.78....485...73.7.42.8.5.25..7..8.87.4.5.14.1.8..27 ..........12.34.56.35.6214.....78....286...37.7.25386..56..7.8..87.2..1.2.1.86.75 ..........12.34.56.35.6214...3.78....286...37.7.25.86..56..7.8..87.2..1.2.1.86.75 ..........12.34.56.35.6214...3.78....286...37.7.25.86..56..7.8..87.2.61.2.1.8..75 .....1..2..1.3..4.243.5.1...1.....6..621.3.57358.6721..253.648..3.8...258.4..56..

Code: Select all: ...........1.23.45.426...31..7.....8.1857.32442..8...7.5.76..8..862.5..3274.38.56 ........1.12.34..56.3.5147...7.18..6.6142..872.8.7.1...25.876.4.7.....588.6.45...

Code: Select all: ...........1..2.34.23154.67.18..5.7..4721..582..7.8.4..82.3...613.8....55.6421.8. ...........1..2.34.3214..56.2.47...8.48921..71.78.5.4..83.1....2.43.8.7.71.25..83 ..........12.34.56.3526.41...17..86...7.281.4.8..4..75..8.7.641.764.258.1...8...7 ........1....2345..456.123...7...84..54.6871..8...75.3.7.1..32.4...82.7.52.7.6184 ........1.12.34....5316..42..1.7..8..8742.1.652.81.7.4.38.425.7.7.3.....2.5.8.4.3 ........1.12.34.5..356.1.24..71.3.82.8..7....2534.8.17.7...62..32..47..55.63...78 ........1.12.34.5..356.1.24..71.3.85.8..7....5234.8.17.7...65..2.63...7835..47..2 ........1.23.1456..14756.23....8.1...814.5.3643..71.58..85......4..6..8.37..486.5

Code: Select all: ...........1..2.34..3.412.5..61.5.4..1...65.23..427.61..87...26.3..647.8.672.8453 ...........1..2.34.2..536.1....26..7.7.5.83.6.863.7125..87.451..172854.3.4..3.7.. ...........1..2.34.23154.67.18....7..4721..582..7.8.4..8253...613.8....55.6421.8. ...........1..2.34.5..3461.....78.53.7.5..84..85243.76.16.27.8..2..81367.38..5..1 ...........1..2.34.5..3461.....78.53.7.5..84..85243.76.16327.8..2..81.67.38..5..1 ...........1.23.45.2345..61..7.4...6.1637.5.4.3.5.6.72.782...5.1..73...83.2.85.17 ...........1.23.45234.567.1....8...7.12.758.4.87..215..26.....8.5823..161.3.685.. ...........1.23.4524..1563..143.2.7676..5....8.2.7.45..26..7.8.17.2.8.644.8..1..7 ...........1.23.4524..1563..26..7.8.17.2.8.644.8..1..75143.2.7676..5....8.2.7.4.. ...........1.23.45243..5.16.2.7....83.82...747...38.6.1...8...74325.7.818.7.1245. ...........1.23.45263.4517...4...78.1.8.37.646.7.845.1.463.281.31...8...8.2.....6 ...........1.2345624..56.17.3...8.2.1.8.32.6442.61..833.4.81.7551......88....5.4. ..........12.34.56.35.2614......7..8..136.57..7..5861..27.8.46.1.8.4.7..54..73.81 ..........12.34.56.35.2641......7..8..136.57..7..5816..27.8.64.1.8.4.7..54..73.81 ..........12.34.56.35.2641......7..8..7.1856..5.26.17..73.8.64.1.4.72.8558..4.7.. ..........12.34.563.56.1427.....3...1.846..322.31.8564.278...4.5.....2.88.1.4..75 ..........12.34.563.56.1427.....3...1.846..355.31.8264.578...4.2.....5.88.1.4..72 ..........12.34.563.56.1427.....3...2.31.85648.146..32.278...4.1.8.4..755.....2.8 ..........12.34.563.56.1427.....3...5.31.82648.146..35.578...4.1.8.4..722.....5.8 ........1.....234....13..2...5..1.6..76384.1581.5.6473.6.84...2.8.2.563.52.6.3.84 ........1..1..234.23..14.56.1527.68.3.7.48.1.82...1.7..53...86..8...5..77.2.86.35 ........1..1.23..4..5.1426.....5.7...5837.4267.64821.5..7..8....84.3.6.26..2458.7 ........1..1.23.4..2415.673..281.4.6.48.65.121....2.5...758.3.4.83....6.4...36.87 ........1..2.13..4.41.2536..173.....284.7163.63..82.17.26..784..782....64....8.7. ........1..2.1345.14.62573...7.68..362.53..8.8....25...1.3.687..76.813.5.8..5..1. ........1..2.1345.14.62573...7.68..562.35..8.8....23...1.5.687..76.815.3.8..3..1. ........1.12.34.5..3516.2.7....4..82.84...5..523.8..74..8..6....4681.7.5351.72.68 ........1.12.3456.5.3.71428....1..8...146...56.5.87.14..6.....2.27.4685..5.72..46 ........1.23.1456..1527643......285..5..6....2.4.58.76.4162.38..8...3.1.3.2.816.. .....1..2.13....4.25.46..31..274..83.37.862.4.8...3.7..21.74.68.7..184258..6.....

Code: Select all: ...........1..2345.32.4561...5..783..185..7.43.74.85.1.86.....315...6.8.2.38.41.6 ...........1.23.45.645...27..2....18.1823.47664.18...2.56.7..8..8.3...544.385.76. ...........1.23.452345.67.1..7.....84....7.166182..4.7.42..8.63.836.21.41.63..8.. ..........12.34.56.35.621.4.....76...68341.7..71.96.4..274138...8..7.4.21...28..7 ..........12.34.563.456.721....53172..76...3.1.34..5.8..1..6.852...8....6.8.45217 ..........12.34.563.56.1427.....3.8.1.846..322.31.8564.278...4.5.....2..8.1.4..75 ..........12.34.563.56.1427.....3.8.1.846..355.31.8264.578...4.2.....5..8.1.4..72 ........1.12.34.5..536.1.24..5.63..7.27.4856.3..7...1..78......2.1.86.7553.4.7.82 ........1.12.34.5..536.1.24..5.63..7.27.4856.3..7...1..78......23.4.7.855.1.86.72

Code: Select all: ..............1.23.24.3..51..1.6..7..461.73.575..84.16.684.2537.72..6..84.58...62 ..........12.34.56.3516.42...7..3.8..63.1.27.128.47.35.71.865.2.8....7..2...7..68 ..........12.34.56.3526.41...73...6..26.47...1.3.2674..58.12.7..7..8....261.7358. ..........12.34.563.456.721....531.2..76...3.1.34..568..1..6.852...8....6.8.45217

Code: Select all: ...........1.23.45.26.4173...2..5.8..5821.36.16..38....1537.8...8..5247.2...865.3 ...........1.23.45.26.4173...2..5.8..5821.36.16..38.5..1537.8...8..5247.2...86..3 ..........12.34.565.78.1423.....7....513...747.84.6.35....4..68..56.83.7.86.7354. .....1..2..1.3.45.243.5617...267.58..8....7..6.7..8.24..81...4..24.6581.1.6.8.2.5 .....1..2..1.3.45.243.6517...267.58..8....7..6.7..8.24..81...4..24.5681.1.6.8.2.5

Code: Select all: ..........12.34567.352.6481.....3..5.237..64.5.76.82.3..1..78...5..8...6.78.6.154 ........1..2..3.4..53146.27..1..8.....86.5.145..4.1.83.853.74.22.7564.383..8...7. ........1.12.3456..536.124......71...7134..2523.1.547..2.7......874.36.23.6...75. ........1.12.3456..536.124......71...7134..252381.547...74.36.2.2.7.....3.6...75. .....1..2..1.3245..4256..31..73....54.6.7.32.5...26.47.7..53.141......7.6.4.17.83 .....1..2..1.3245..4256..31..73....54.6.7.32.5...26.47.78.53.141......7.6.4.17..3

Code: Select all: ...........1.23.45.241...36..37.....2.73.84.14.85.2.73.462.158.1.28.5.648....6.1. ...........1.23.45.241...36..73.....2.37.84.14.85.2.73.462.158.1.28.5.648....6.1. ...........1.23.45234..5.16..7..4.3..4.2.8.575231.7.84.12.8..7..7.3....83.87.2.61 ...........1.23.45234..5.16..7..4.3..4.238.5752.1.7.84.12.8..7..7.3....83.87.2.61 ...........1.23.45234..5.61..7..4.3..4.2.8.575231.7.84.12.8..7..7.3....83.87.2.16 ...........1.23.45234..5.61..7..4.3..4.238.5752.1.7.84.12.8..7..7.3....83.87.2.16 ........1..1.23.4.254.613.......67..462.378.57..28...41.635.47.3.7.1..5.54..721.. ........1..1.2345..42.16.37..4.87....2.3.5..8.582.1.43.85.3..7.2.7.583.44....2.85 ........1..1.2345..42.16.37..4.87....2.3.5..8.852.1.43.58.3..7.2.7.583.44....2.85 ........1..2.13.4..51.64..7..5.8.....68..1.7471.42..58.2.6...83.36.487.2.87.3246. ........1..2.13.4..51.64..7..5.8.....68..1.7471.42..58.26.487.3.3.6...82.87.3246. ........1..2.13.4..51467.32.......8..26.783.4.8734..16..8..4...2..73..687.5.81423 ........1.12.34.5.5.31.624......7..6.2.64.7...7.3.8425..1....7..374.156226.7.31.4

Code: Select all: ...........1..2.34.23.546.1..7.6..12.32..57.61.62.7345.187.6453.745..1..3.......7 ...........1.23.45.23.4561...7..48...46.18.573.8.5746..3..82.76.7.53..8.8.2.7.5.. ...........1.23.45.24.516.3.172.45.8.48.3...72...78.64.763.28...8..1..7.1.2.87..6 ...........1.23.45.421...36...7.....2845...737.638.45..682.751.1.7..8.6.42.6.1.87 ...........1.23.45.451...23..4..637..5673.4.2.7.2...56.17.68234.38.12.6..6..7...8 ...........1.23.4524..15.63.....7..8.84.5..7.73..8145..13.7268..2.1.4.3747..38.2. ...........1.23.4524..15.63.....7..8.84.5..7.73..8145..13.72684.2.1.4.37.7..38.2. ...........1.23.4524..5631...6.72458..7.......8256.73.1.3.875.47.461..8.8...3.17. ...........1.23.4526.4.137...........12534.8.7.8162.34.263.5..71.7..6.535...1746. ...........1.23.4526.41.37...........18542.3.7.2136.84.2635...71.7.6..535...7146. ..........12.34.56.35.2641...1.73....7.2.1.8.2.346.17...7.8..4..2...7.68.5864273. ........1....2345..24156.37.....8......26517.26..14.85.4..3271..8..4...337.68154. ........1....2345..24156.37.....8......26571.26..14.85.4..3217..8..4...337.68154. ........1..2.13.4..51467.32.....6.8..26.783.4.8734..1...8..4...2..73..687.5.81423 ........1..2.13.45.13.5627......14....1362.5.3.75.41.6.38.2..64.746358.22....8... ........1..2.13.45.136457.2....8.....87.342.632...68.4..1..7..823.4581.77...614.. ........1..2.13.45.136457.2....8.....87.362.432...48.6..1..7..823.4581.77...614.. ........1..2.13.4513..546...4..3.7.6263.75..87....8....8..47.6.3.75.6..442.3815.7 ........1..2.13.4513..546...4..3.7.6263.75..87....8....8..47.6.3.75.6.8442.3.15.7 ........1.12.34.5..635.1.2...47...8..284.37.5.3..85....76.581...81.4657.3..1.7.68 ........1.12.34.5.5.3.162.4..4.7..8..57.834.23.8.427.5.3...8..7.7536..288.1..7... .......12..1.234...25.16378...3....1.1..6854.5.8.41.63..6..2..4.4268..3585..3..2. .......12..1.2345..25.16378...3....1.1..6854.5.8.41.63..6..2..4.4268..3.85..3..2.

Code: Select all: ...........1..2.34.321456.7..62518...284.6...1...38..6.875.43..213.874..5...2.7.8 ...........1..2345.32.45.6...7.....432..7485.4.5.28.37.53.87.16.7..1.58.1.8..6.73 ...........1.23.45243..5.61....5...71.2.475867..2.8.1..18.746.24......786.78.2.54 ...........1.23.45243..5.61....5...71.2.475867..8.2.1..18.746.24......786.72.8.54 ...........1.2345624..5137..67..58..4...38...8...6.54..74.862.55.8.726.462....78. ..........12.34.56.345.621...1.57....47.136.53..6.217...8.7..62.23.6578..7...85.. ........1....2345..24156.37.....8......26517.26..14.85.4..32718.8..4...337.6.154. ........1....2345..24156.37.....8......26571.26..14.85.4..32178.8..4...337.6.154. ........1..2..3..4.13.4526...1..78...2.4.8.17.87..1642.5..7.....785.4.262348.6.75 ........1..2.13.45.5124.3....6..78.4.1863.7..5.7.28.36.25.81.63.6.3.25.8.8..6.... ........1..2.13.4513..54.26.53.781.2.7...1...21.53..74.8..4.2..3...8..5772.3.54.8 ........1.12.34.5..35.164.2..3..784..584.31.7.7..8.....276.85...81..27.454..712.. ........1.12.34.5..35.164.2..3..784..584.31.7.7..8.....276485...81..27..54..712.. ........1.12.34.5.6.317..48....2..1..31457.262.631.4.5....83.64..8...5..36.74..82

The source code is available at https://github.com/dobrichev/sudoku35plus

by **dobrichev** » Tue May 26, 2015 4:49 pm

The next batch.

Hidden Text: Show

It is harder and harder to do more 39s.
Discovering of more 40-givens puzzles has less chance than discovering of green creatures living on Mars.
There are still much 36s to discover. The derivative 37s and 38s are exhausted quickly.

by **dobrichev** » Thu Jul 02, 2015 9:26 pm

The next batch.

Hidden Text: Show

Code: Select all: ..............1.23..1..2.45.36.1..57215.7346.4.7..6.3..68.27..41436.8.727.21...8. ...........1..2.34.5..34.16..7..8..351..43.878.3.75142.2.....7..75.86.211.8.2746. ...........1..2.34.5..34.16..7..8..351..43.878.3.75142.25.86.71.7.....2.1.8.2746. ...........1..2.34.5..34.61..7..8.4.51..43.788.4.75123.2......7.75.86.121.8.273.6 ...........1..2.34.5..34.61..7..8.4.51..43.788.4.75123.25.86.17.7......21.8.273.6 ...........1..2345.341652.7...5..7.8.8..2..3.7.3.1852...6.5.8....82.16.3.17.86452 ...........1..2345.341652.7...5..7.8.8..2..3.7.3.1852...62.18.3..8.5.6...17.86452 ...........1.23.45.421...63..73.84...8..16..713.2.7.86..87.1..441.532.787.38...5. ...........1.23456.45.172.3.....1845.1..5....4.6.7813...2.8..64.64.325.858...632.

Code: Select all: ..............1.23124..3.56..1..6.782.7.8.3.14.81.756264..58..77......8.8.27.4635 .............12.34.135..627....7..82..7..845..81245.76..8.23..5.3.457.68.7.8.1.43 .............12.34123.45.67.38.21..66.......871..683.2.8...4.7.2.4.57.8337..864.5 .............12345.13.467.2..1.842.3.82...45.3...25..8.36..8..7.78.615341.5.7.8.. ...........1..2.34.23.145.6..762...8.1.4.8.57.38.71642.72...46.1.52.6.733....7..5 ...........1..2345.23.45.1...6.....7.35..746.2.76.4531.62....7.31..7865.7.84.61.3 ...........1..2345.23.451....6.....7.35..746.2.76.4531.62...7..31..7865.7.84.6.13 ...........1.23.45.24.153.6..7..28...1..876.4.4813...7.7..5846..85.6..734...715.8 ...........1.23.45.24.5..63.......7..17.8653448.73..21.723.8..61.8.62..764.57...2 ...........1.23.45.245.6.31..23...67..62.54.3.4..67.5..18.5237..6713...82....8.14 ...........1.23.45.2465..31..2....7..7623.1.441..675...47.8....1.83.2.5723..76.18 ...........1.23456.45.172.3.....184..1..5....456.7813...2.8..64.64.325.858...632. ..........12.34.56.35.6742....6.158..81.4..7.52..78..4..87...4515..832672....68.. ..........12.34.56.3526.4.1..1.7..8..5.8..7.4.7842.615.2......81..34.5625.3.8.1.7 ..........12.34.56.3526.4.1..1.7..8..5.8..7.4.7842.615.2......81.3.8.5.75..34.162 ..........12.34567.345.6812..8..5.71.2.7.865..7....2...4..83125.83.5...62....738. ........1.....2.3..34.15.2...6..7.58.48.5617.7.51.8.64.638.471..8..7...64.7.61.83 ........1..1..2.3..3...4256..7.83..518.4.7.2334.2...87.74.21.6861..48.728..7.6... ........1..1.23.4..42.51367..4.82..6.1856.432.6..1...8..7..8....8.23..7442..75.83 ........1..2.13.4..1354.2....6.78.52.2835..675.7.6.81..846.....2.143..8.36..8..24 ........1..2.13.4..14.5.236..7..8.6..4653..78.8376.452.2.37..14.71.8..2.43......7 ........1.12.34..5.356.124......7....28345.76.731..4.2..7...6...867.35.435.4.6.27 ........1.12.34.5..6351.247..1.57.26.2.1.....6.74..1.5.36..57...7834.5622...7...3 .....1..2..2.3.45.34..521.6..4.735.1.7.....6..8316.7.4.2731..45.365..2.74...27...

Code: Select all: ...........1..2.3425.36..17..7.4..2.4.8..5.76526.37.4.175.26.836...8....8.2.53.61 ...........1..2.3425.36..71..7.4..2.4.8..5.67526.37.4.175.26.836...8....8.2.53.16 ...........1.23.45234.56.71.....1.8..42.685.78.32.541..27.8....3.86.27.44.6.3...8 ...........1.23.45234.56.71.....1.8.142.685.78.32.54...27.8....3.86.27.44.6.3...8 ..........12.34.56.35.2614...7.824...2...7.681..64..7..732.1.84.8..73...2.1.6873. ..........12.34.56.3526.4.1..1.7..8..5.8..7.4.7842.615.2......81..34.56.5.3.821.7 ..........12.34.56.3526.4.1..1.7..8..5.8..7.4.7842.615.2......81.3.825.75..34.16. ..........12.34567.345.6812..8..5.71.2.7.86...7..6.2...4..83125.83.5...62....738. ..........12.34567.345.6812..8..5.71.2.7.865..7..6.2...4..831.5.83.5...62....738. ........1....12.3..14.536.2....7..8...73.82...83.257.6..1..79...985361.77.5.91368 ........1..1.23.4..541.6.32.....2.7..45.37.26.726.53.4..7......4.8.61.575.6.78413 ........1..1.23.4..541.6.32.....2.7..45.37.26.726.54.3..7......4.8.61.575.6.78314 ........1..1.23.4..541.6.32.....7.2..45.32.76.726.53.4..7......4.8.61.575.6.78413 ........1..1.23.4..541.6.32.....7.2..45.32.76.726.54.3..7......4.8.61.575.6.78314

Code: Select all: ..............1234..2.3.5.6..7.864...461.7..3.8134.6.7.2.7....8.584137.2.74.283.5 ........1.12.34..5.36.51.2...3.17.48.483.25.7.6..482...8....7..3...75.8667..831.2 ........1.12.34.5.36..51.42....7..1..314.5.87.76.124.5..7.4..28.2358..74.8...75.. ........1.12.34.5.6.31.52.7.....3..5.2584.....365.7428..1.7..8...74.81.22.83.1.74 ........1.12.34.566.5.12347..1.6.47..7634.1.55....1..3..8..7.34.5..2.....6748.5.2 .....1..2..1.3..4.45..6..3...6....78.8567.4.374..1826..1875.324.7..8....5.412..87

Code: Select all: .............12.34.13.456.2.4..5.7.3.71.8.4..3.6.74.28.87.2.3.613..682.76....7.81 .............12.34.13.456.2.41.7.8...8..5.4.33.6.84.27.78.2.3.613..672.86....8.71 ...........1..2345.3456172......8.7..836.751.7.61.583...8.1425..428.....1..2.648. ........1..2.34..5.36.51.2...3.17.48.483.25.7.6..482...8....7..32..75.8667..831.2 ........1.12.34.566.5.1234...1.6.47..7634.1.55....1..3..8..7.34.5..2.7...6748.5.2

Code: Select all: ........1....23.4..25.413....6..47..2...76.347.4238.16.62.85.73.8..6..5.5.73.2.68 ........1..2.13.4.14..52.36....783.4.74531.688..2...57.17.2..8..25.876.3.8...5.7. ........1..2.13.4.14..52.36....783.4.74531.688..2...57.1732..8..25.876...8...5.7.

Code: Select all: .............12.34.153...26....7..4..4123...776.1.4.53..67....815486..7287.421.65 ..........12.34.56.35.267.1.24.8.5.7.586.7.121.7..2..8.43.681.5.8.4.....5....3.84

Code: Select all: .....1..2..3.4.56..2536.41...76..1...61.73.2423..1467..5...7.4..7..3.2..3.248.75.

Code: Select all: ........1..2.13.4.14..523.6.26.7143.3.426.1.77...3.....6....7..2.5.876.44.7.2658.

by **Mathimagics** » Wed Apr 10, 2019 7:27 pm

Just a note to advise that one of dobrichev's 40-clue minimal puzzles (still the highest known number of clues for a minimal puzzle) also has an 18-clue puzzle on the same grid:

Code: Select all: ..........12.34567.345.6182..1.582.6..86....1.2...7.5...37.5.28.8..6.7..2.7.83615 40-clues 5........81....5.......6..2...3...9.3..6.2.7.......8...6..1......5....3.....8...5 19-clues ......34.81...4...9.................3...9...1.....7.5..6..1.9.8..5........7.8.... 18-clues 576821349812934567934576182741358296358692471629147853463715928185269734297483615

Coincidence? 8-)

Note: I have not excluded the possible existence of a 17-clue puzzle on this grid, perhaps someone might do that?

by **coloin** » Sun Apr 14, 2019 9:14 am

Mathimagics wrote:Coincidence? ?

unfortunately not :roll:

.... maybe one in three solution grids have an 18, almost all solution grids have at least one 19 ....
the MC grid doesnt have a 19 and only has one ED 20-puzzle

by **Mathimagics** » Sun Apr 14, 2019 11:06 am

Ok, no big deal then.

Thanks coloin! 8-)

by **Mathimagics** » Thu Oct 10, 2019 5:13 pm

I believe this is a new 39-clue minimal puzzle:

In puzzle minlex form:

Code: Select all: ..........12.34567.345.6128..1.582.6..86....1.2...7.5...37.5..2.8..6.7..2.7.83615 576821349812934567934576128741358296358692471629147853463715982185269734297483615

In grid-canonical form:

Code: Select all: 1..4....9.5..8..2..981.2..4..1..5.9.58.2....7.798412.5.67518.4281.924.76......... 123456789456789123798132564231675498584293617679841235367518942815924376942367851

This was found by processing one of Mladen's famous 40C minimal puzzles with his sudoku35plus tool (https://github.com/dobrichev/sudoku35plus). I am trying to establish whether or not the only known grid with a 40C also has a 39C, and this seemed like a relatively quick way to find one ...

But no, because the 40C grid and the 39C grids differ ever so slightly (by a UA4):

Code: Select all: 123456789456789123798132564231675498584293617679841235367518942815924376942367851 # CF soln to the 39C above 123456789456789123798132564231675498584923617679841235367518942815294376942367851 # CF soln to the 40C ** **

So, I have not actually demonstrated that the 40C grid has a 39C, but neither can I say that it doesn't. This question remains open.

If it could be proven that there is no 39C minimal puzzle on the 40C grid, then this would be significant for the (notional) "High Clue Threshold" project, at least as far as any "minimal puzzle continuity" conjecture" is concerned. This refers to whether or not all grids have minimal puzzles of EVERY size, from the least-clues case throught to the most-clues case.

by **dobrichev** » Thu Oct 10, 2019 6:14 pm

Only to mention that your puzzle is very close to one published on page 10 of this topic and to the one on line 1545 in this file.

The New Sudoku Players' Forum

High clue tamagotchis

Re: 2250+4+9+9+3+5+18+8+1+7+4+1+1+2=2322

Re: High clue tamagotchis

Re: High clue tamagotchis

Re: 2250+4+9+9+3+5+18+8+1+7+4+1+1+2=2322

2322+17+10+6+19+29+21=2424

2424+9+7+14+2+8+30+9+4+5+6+13+23+14=2568

2568+8+3+1+2+2+1=2585

2585+9+24+14+6+5+3+2+1+1=2650

Minimal 40-clue Puzzles

Re: Minimal 40-clue Puzzles

Re: High clue tamagotchis

New 39C minimal

Re: High clue tamagotchis