The New Sudoku Players' Forum

by **urhegyi** » Thu Aug 27, 2020 6:24 pm

: 2020-08-27 (2).png (147.29 KiB) Viewed 1184 times

How do I start solving duo sudoku?

by **1to9only** » Thu Aug 27, 2020 7:44 pm

The 2 sudokus (as separate sudokus):

Code: Select all: ...........27.3.1..8....6.5.9.43...2...91.....4.........7.......3.....96..93...54 43...29..91.....6.......1.........2.....96...3...54.1.5.3....7..6.4.92...........

The pencilmarks:

Code: Select all: +-------------------------+-------------------------+-------------------------+ | 1345679 1567 13456 | 12568 245689 1245689 | 234789 23478 3789 | | 4569 56 2 | 7 45689 3 | 489 1 89 | | 13479 8 134 | 12 249 1249 | 6 2347 5 | +-------------------------+-------------------------+-------------------------+-------------------------+ | 15678 9 1568 | 4 3 5678 | 1578 678 2 | 9 58 578 | | 235678 2567 3568 | 9 1 2578 | 3578 3478 378 | 34578 6 234578 | | 1235678 4 13568 | 268 2578 25678 | 35789 3678 378 | 1 3458 234578 | +-------------------------+-------------------------+-------------------------+-------------------------+ | 124568 1256 7 | 168 4589 145689 | 138 38 138 | 345678 2 3456789 | | 12458 3 1458 | 128 24578 124578 | 1278 9 6 | 34578 3458 34578 | | 1268 126 9 | 3 278 2678 | 278 5 4 | 678 1 6789 | +-------------------------+-------------------------+-------------------------+-------------------------+ | 5 2489 3 | 1268 1268 18 | 468 7 14689 | | 178 6 178 | 4 1378 9 | 2 358 1358 | | 1278 24789 124789 | 1235678 123678 13578 | 34568 34589 1345689 | +-------------------------+-------------------------+-------------------------+

There are some hidden singles in both grids to start off with:

Grid 1:

Hidden Text: Show

Grid 2:

Hidden Text: Show

To solve requires basic techniques up to naked/hidden pairs.

by **urhegyi** » Thu Aug 27, 2020 10:12 pm

I just solved this completely by hand
176548329952763418384291675795436182863912547241875963427659831538124796619387254
436182957912547368875963142659831724124796583387254619593628471768419235241375896
It took a couple of hours. Is your addon to sudokuexplainer capable of printing out the solution path? I know it can do it with a basic sudoku, but can it be done with this variant to? Thanks for your quick response. It helped me lot.

Peter

by **Hajime** » Fri Aug 28, 2020 7:50 am

With SiSeSuSo this a possible result.
Be aware the logging (solution path) can be different per solver.

Hidden Text: Show

Code: Select all: Step Sol Grid Row Col Val Why 1 1 1 5 8 4 HS in row 1 2 1 6 7 9 HS in row 1 3 1 1 4 5 HS in col 1 4 1 7 9 1 HS in col 1 5 1 4 7 1 HS in box 1 6 1 5 7 5 HS in box 1 7 2 7 6 8 Naked Single 1 8 2 6 9 9 HS in row 1 9 2 7 2 9 HS in row 1 10 2 9 8 9 HS in row 1 11 2 4 3 9 HS in col 1 12 2 9 6 5 HS in col Explanation:NSS (37)1b6_69 means: Naked Subset of candidates 3 and 7 in Grid 1, box 6, element (position) 6 and 9 Hidden/Naked subsets | NSS (37)1b6_69 => (-7)1r4c8 (-37)1r6c8 | NSS (368)1r7c478 => (-68)1r7c1 (-6)1r7c2 (-8)1r7c5 | NSS (38)1r7c78 => (-8)1r7c4 | NSS (68)1c8r46 => (-8)1r1c8 (-8)1r7c8 | NSS (368)1c8r467 => (-3)1r1c8 (-3)1r3c8 | NSS (6)1b8_1 => (-6)1r9c6 | NSS (278)1r9c567 => (-28)1r9c1 (-2)1r9c2 | NSS (37)1c9r56 => (-37)1r1c9 | NSS (38)1b9_12 => (-8)1r8c7 (-8)1r9c7 | NSS (3)1b9_2 => (-3)1r7c7 | NSS (6)2c1r4 => (-6)2r3c1 | NSS (6)2r4c1 => (-6)2r4c7 (-6)2r4c9 | NSS (68)2r4c14 => (-8)2r4c7 (-8)2r4c9 | NSS (368)2r4c145 => (-3)2r4c7 (-3)2r4c9 | NSS (278)2c4r456 => (-2)2r7c4 (-27)2r9c4 | NSS (2678)2c4r4567 => (-6)2r9c4 | NSS (68)2c5r13 => (-6)2r7c5 (-6)2r9c5 | NSS (368)2c5r134 => (-3)2r8c5 (-3)2r9c5 | NSS (278)2r6c234 => (-78)2r6c7 | NSS (6)2r7c4 => (-6)2r7c7 (-6)2r7c9 | NSS (46)2r7c47 => (-4)2r7c9 | NSS (146)2r7c479 => (-1)2r7c5 | NSS (6)2c7r6 => (-6)2r9c7 | NSS (46)2c7r67 => (-4)2r4c7 (-4)2r5c7 (-4)2r9c7 | NSS (178)2r8c135 => (-8)2r8c8 (-18)2r8c9 | NSS (26)2b8_12 => (-2)2r9c5 | NSS (123478)2r9c123457 => (-1348)2r9c9 | NSS (3)2r9c4 => (-3)2r9c7 | NSS (38)2r9c47 => (-8)2r9c1 (-8)2r9c2 (-8)2r9c3 3 13 1 7 4 6 Naked Single 3 14 1 7 7 8 Naked Single 3 15 1 7 8 3 Naked Single 3 16 1 1 7 3 HS in col 3 17 1 2 7 4 HS in col 3 18 2 6 7 6 Naked Single 3 19 2 7 4 6 Naked Single 3 20 2 7 5 2 Naked Single 3 21 2 7 7 4 Naked Single 3 22 2 7 9 1 Naked Single 3 23 2 9 4 3 Naked Single 3 24 2 9 7 8 Naked Single 3 25 2 9 9 6 Naked Single Hidden/Naked subsets | NSS (16)1b7_78 => (-1)1r8c1 (-1)1r8c3 | NSS (37)2r2c67 => (-7)2r2c3 (-37)2r2c9 Hidden/Naked subsets | NSS (28)1b5_67 => (-8)1r4c6 (-28)1r6c5 (-28)1r6c6 Pointing (P) /Claiming (C) | C (6)1c5b2 => (-6)1r1c6 | C (6)1r5b4 => (-6)1r4c1 (-6)1r4c3 (-6)1r6c1 (-6)1r6c3 | C (2)1r7b7 => (-2)1r8c1 | P (8)1b7r8 => (-8)1r8c4 (-8)1r8c5 (-8)1r8c6 | C (8)2c2b4 => (-8)2r6c3 | C (7)2r4b6 => (-7)2r5c7 (-7)2r5c9 | C (5)2c7b6 => (-5)2r4c9 (-5)2r5c8 (-5)2r5c9 | C (7)2c1b7 => (-7)2r8c3 (-7)2r9c2 (-7)2r9c3 7 26 1 9 5 8 HS in row 7 27 1 6 4 8 HS in col 7 28 1 1 6 8 HS in col 7 29 1 4 8 8 HS in col 7 30 1 2 9 8 HS in col 7 31 1 1 9 9 HS in col 7 32 1 5 6 2 HS in box 7 33 1 6 8 6 HS in box 7 34 2 1 8 5 Naked Single 7 35 2 1 9 7 Naked Single 7 36 2 2 7 3 Naked Single 7 37 2 2 9 8 Naked Single 7 38 2 3 8 4 Naked Single 7 39 2 3 9 2 Naked Single 7 40 2 4 9 4 Naked Single 7 41 2 5 7 5 Naked Single 7 42 2 5 9 3 Naked Single 7 43 2 6 3 7 Naked Single 7 44 2 6 4 2 Naked Single 7 45 2 8 8 3 Naked Single 7 46 2 8 9 5 Naked Single 7 47 2 1 3 6 HS in row 7 48 2 2 6 7 HS in row 7 49 2 3 6 3 HS in row 7 50 2 3 2 7 HS in row 7 51 2 4 2 5 HS in row 7 52 2 4 7 7 HS in row 7 53 2 5 4 7 HS in row 7 54 2 5 8 8 HS in row 7 55 2 8 3 8 HS in row 7 56 2 3 3 5 HS in col 8 57 1 4 3 5 Naked Single 8 58 1 5 2 6 Naked Single 8 59 1 6 3 1 Naked Single 8 60 1 7 2 2 Naked Single 8 61 1 9 2 1 Naked Single 8 62 1 1 1 1 HS in row 8 63 1 4 1 7 HS in row 8 64 1 6 1 2 HS in row 8 65 1 7 1 4 HS in row 8 66 1 8 1 5 HS in row 8 67 1 8 3 8 HS in row 8 68 1 9 1 6 HS in row 8 69 1 5 1 8 HS in col 8 70 1 2 2 5 HS in col 8 71 1 1 2 7 HS in col 8 72 1 1 3 6 HS in col 8 73 1 2 5 6 HS in col 8 74 1 3 5 9 HS in col 8 75 1 3 8 7 HS in col 8 76 1 3 3 4 HS in box 8 77 1 2 1 9 HS in box 8 78 1 1 5 4 HS in box 8 79 1 1 8 2 HS in box 8 80 1 5 3 3 HS in box 8 81 1 8 6 4 HS in box 8 82 2 5 2 2 Naked Single 8 83 2 9 2 4 Naked Single 8 84 2 9 3 1 Naked Single 8 85 2 9 5 7 Naked Single 8 86 2 5 1 1 HS in row 8 87 2 8 5 1 HS in row 8 88 2 8 1 7 HS in row 8 89 2 9 1 2 HS in row 9 90 1 3 1 3 Naked Single 9 91 1 3 4 2 Naked Single 9 92 1 3 6 1 Naked Single

by **enxio27** » Fri Aug 28, 2020 2:46 pm

Out of curiosity, where did this puzzle come from?

by **urhegyi** » Fri Aug 28, 2020 3:15 pm

enxio27 wrote:Out of curiosity, where did this puzzle come from?

It was posted on a facebook group with sudoku puzzles: https://www.facebook.com/groups/722318601312015/

by **urhegyi** » Fri Aug 28, 2020 3:33 pm

: 2020-08-28 (2).png (60.13 KiB) Viewed 1137 times

I found another one : as someone could explain how I can generate the pencilmarks myself, doing it by hand takes a long time.

by **Hajime** » Fri Aug 28, 2020 3:45 pm

urhegyi wrote:... as someone could explain how I can generate the pencilmarks myself, doing it by hand takes a long time.

By posting it on this forum

Code: Select all: +------'------'-----+------'-----'-----+-----'-----'-----+ | 7 1689 1469| 2 3468 5 | 1369 1368 1389| | 146 1268 1246| 13467 9 13678|12367 12368 5 | | 1569 125689 3 | 167 678 1678| 4 1268 12789| +------'------'-----+------'-----'-----+-----'-----'-----+------'-----'----+ | 2 1356 1567| 1457 34578 137 | 135 9 134 |123478 6 178| | 1359 4 1579| 1579 357 12379| 8 235 6 |123479 23479 179| | 8 13569 1569| 1469 346 12369| 123 7 134 | 5 23489 189| +------'------'-----+------'-----'-----+-----'-----'-----+------'-----'----+ | 34569 23569 8 | 5679 1 3679| 3569 3456 3479| 4789 45789 2 | | 13569 123569 12569| 8 3567 4 |23569 2356 379 | 79 1 5679| |134569 7 14569| 569 2 69 | 1569 4568 1489| 4789 45789 3 | +------'------'-----+------'-----'-----+-----'-----'-----+------'-----'----+ |124579 4579 8 | 3459 345 3459| 6 23579 1579| | 3 45679 25679| 4569 1 4589| 2789 25789 5789| | 1569 569 1569| 7 3568 2 | 1389 3589 4 | +------'-----'-----'-----'-----'-----'------'-----'----+ #2//B4/E10 7..2.5.......9...5..3...4..2......9..4....8.68......7...8.1.......8.4....7..2.... ....9..6....8.6.......7.5...1......28.4....1..2......3..8...6..3...1.......7.2..4

by **creint** » Fri Aug 28, 2020 4:51 pm

With my solver:
First one only one step with one or more locked singles required.
Second one only singles.

by **1to9only** » Fri Aug 28, 2020 5:53 pm

urhegyi wrote:I found another one : as someone could explain how I can generate the pencilmarks myself, doing it by hand takes a long time.

SudokuSolver by Richard Broughton can help with this Sensei-4/DoubleDoku puzzle.
Download from his website: http://www.rcbroughton.co.uk/sudoku/ss_index.htm

Here is a quick summary of how to obtain the pencilmarks for the first puzzle:

- You'll need the 2 line sudokus representation of the puzzle

Code: Select all: ...........27.3.1..8....6.5.9.43...2...91.....4.........7.......3.....96..93...54 43...29..91.....6.......1.........2.....96...3...54.1.5.3....7..6.4.92...........

- copy the 2 lines to the clipboard

- Start SudokuSolver
- Select Extended (bottom left)
- Select DoubleDoku puzzle type
- Click on Edit, Paste Into (both grids are loaded from clipboard)
- Press F2 - for Mode (Solve)
- Click one of the buttons to Make one Solver step (this will only highlight the pencilmarks)
- Click on one of the givens to keep the updated pencilmarks
.

by **urhegyi** » Fri Aug 28, 2020 9:42 pm

I just solved my 2nd example by hand.
grid 1 :716245938482396715953178462267481593149753826835962174528617349691834257374529681
grid 2 :481593267753826149962174538617349852834257916529681473278435691346918725195762384
Now I finished it manually, can someone publish a computer based solution, so I can compare with mine.
Thanks,

Peter

by **urhegyi** » Sat Aug 29, 2020 9:20 pm

: 2020-08-29 (2).png (31.48 KiB) Viewed 1083 times

I have found a third example: can someone do the pencilmarks and rate the difficulty?
Thanks,

Peter

by **1to9only** » Sat Aug 29, 2020 9:35 pm

Have you tried the SudokuSolver link I gave a few posts back?

by **urhegyi** » Sat Aug 29, 2020 10:01 pm

1to9only wrote:Have you tried the SudokuSolver link I gave a few posts back?

Yes, meanwhile I have generated 2 separate pictures of each grid with the pencilmarks. Is there a possibility to have them in one picture like your first post?

by **1to9only** » Sat Aug 29, 2020 10:06 pm

Code: Select all: +-------------------------+-------------------------+-------------------------+ | 2458 158 7 | 1258 1248 3 | 1256 1246 9 | | 245 6 1245 | 1259 7 12459 | 1235 8 12345 | | 9 1358 12458 | 6 1248 12458 | 7 1234 12345 | +-------------------------+-------------------------+-------------------------+-------------------------+ | 2578 1578 9 | 2378 138 6 | 1358 12347 1234578 | 1234 2345 9 | | 2678 4 1268 | 2379 5 1279 | 1369 123679 1237 | 1234 8 1346 | | 3 1578 12568 | 4 189 1289 | 15689 1269 1258 | 7 235 1356 | +-------------------------+-------------------------+-------------------------+-------------------------+ | 4578 5789 3 | 2579 149 124579 | 19 1279 6 | 12349 23479 8 | | 4678 2 468 | 3789 13489 14789 | 1389 5 1378 | 12349 6 1347 | | 1 5789 568 | 23789 3689 2789 | 4 2379 2378 | 5 2379 137 | +-------------------------+-------------------------+-------------------------+-------------------------+ | 5678 4678 3 | 1567 1467 9 | 48 457 2 | | 5679 2 4579 | 3567 8 3457 | 349 1 3457 | | 1 4789 45789 | 2 347 3457 | 6 34579 3457 | +-------------------------+-------------------------+-------------------------+

i think slighty more difficult than the first one.
SE ratings:

Code: Select all: ..7..3..9.6..7..8.9..6..7....9..6....4..5....3..4.......3.....6.2.....5.1.....4.. ED=2.8/1.2/1.2 ..6.....9.5.....8.4.....7.......6..8....5..6....4..5....3..9..2.2..8..1.1..2..6.. ED=3.4/1.2/1.2

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start solving duo sudoku

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