The New Sudoku Players' Forum

by **P.O.** » Fri Feb 17, 2023 5:06 pm

Code: Select all: . 3 . . . . . 5 . 7 2 5 3 4 6 9 8 1 8 . 4 . . . . . 3 1 5 8 4 2 3 6 7 9 . . . 1 . . . 4 . 2 4 7 8 6 9 1 3 5 . . 2 . . 4 . . . 4 8 6 2 3 1 5 9 7 . 7 . . . . . . . .3.....5.7253469818.4.....3158423679...1...4.247869135..2..4...486231597.7....... 69 3 19 79 1789 278 247 5 246 7 2 5 3 4 6 9 8 1 8 169 4 579 1579 257 27 26 3 1 5 8 4 2 3 6 7 9 369 69 39 1 57 57 28 4 28 2 4 7 8 6 9 1 3 5 359 19 2 5679 5789 4 38 16 68 4 8 6 2 3 1 5 9 7 359 7 139 569 589 58 2348 126 2468

by **SteveG48** » Sat Feb 18, 2023 12:02 am

Code: Select all: *------------------------------------------------------------* | 6-9 3 a19 |a79 a1789 a278 | 247 5 246 | | 7 2 5 | 3 4 6 | 9 8 1 | | 8 169 4 | 579 1579 b257 | 27 26 3 | *--------------------+-------------------+-------------------| | 1 5 8 | 4 2 3 | 6 7 9 | | 369 69 39 | 1 c57 c57 | 28 4 28 | | 2 4 7 | 8 6 9 | 1 3 5 | *--------------------+-------------------+-------------------| | f359 19 2 | 5679 5789 4 | 38 16 68 | | 4 8 6 | 2 3 1 | 5 9 7 | |ef359 7 ef139 | 569 d589 c58 | 2348 126 2468 | *------------------------------------------------------------*

(9=1782)r1c3456 - (2|7=5)r3c6 - 5r59c6 = (58)r5c5,r9c6 - (5|8=9)r9c5 - 9r9c13 = (19)r19c3|(3,59)b7p917 => -9 r1c1 ; ste

by **jco** » Sat Feb 18, 2023 10:57 am

Code: Select all: .---------------------------------------------------------------. |D'69 3 C'19 | 79 1789 278 | 247 5 246 | | 7 2 5 | 3 4 6 | 9 8 1 | | 8 19-6 4 | 579 1579 zd257 |zd27 zd26 3 | |--------------------+---------------------+--------------------| | 1 5 8 | 4 2 3 | 6 7 9 | | 369 D69 C39 | 1 b57 c57 | 28 4 28 | | 2 4 7 | 8 6 9 | 1 3 5 | |--------------------+---------------------+--------------------| | 359 19 2 | 5679 5789 4 | 38 16 68 | | 4 8 6 | 2 3 1 | 5 9 7 | | 359 7 B139 | 569 Axa589 y58 | 2348 126 2468 | '---------------------------------------------------------------'

Double Kraken (589)r9c5, (9)r159c3 => - 6 r3c2; ste

Code: Select all: (5)r9c5 - r5c5 = r5c6 - (5=276)r3c678 || (8)r9c5 - (8=5)r9c6 - (5=276)r3c678 || || (9)r1c3 - (9=6)r1c1 || || (9)r9c5 - r9c3 || (9)r5c3 - (9=6)r5c2

I found later a simple solution in two steps

Hidden Text: Show

Code: Select all: .------------------------------------------------------------. |e69 3 19 | 79 1789 278 | 247 5 246 | | 7 2 5 | 3 4 6 | 9 8 1 | | 8 d16-9 4 | 579 1579 257 | 27 c26 3 | |-------------------+-------------------+--------------------| | 1 5 8 | 4 2 3 | 6 7 9 | | 369 69 39 | 1 57 57 | 28 4 28 | | 2 4 7 | 8 6 9 | 1 3 5 | |-------------------+-------------------+--------------------| | 35-9 a19 2 | 5679 5789 4 | 38 b16 68 | | 4 8 6 | 2 3 1 | 5 9 7 | | 35-9 7 139 | 569 589 58 | 2348 c126 2468 | '------------------------------------------------------------'

1. (9=1)r7c2 - r7c8 = (12-6)r39c8 = (6)r3c2 - (6=9)r1c1 => -9 r79c1, -9 r3c2 [6 placements and basics]
-----
Step 2

Code: Select all: .--------------------------------------------------. | 69 3 *19 | 7 *18 28 | 24 5 246 | | 7 2 5 | 3 4 6 | 9 8 1 | | 8 16 4 | 59 19 25 | 7 26 3 | |----------------+----------------+----------------| | 1 5 8 | 4 2 3 | 6 7 9 | | 69 69 3 | 1 5 7 | 28 4 28 | | 2 4 7 | 8 6 9 | 1 3 5 | |----------------+----------------+----------------| | 35 19 2 | 569 7 4 | 38 16 68 | | 4 8 6 | 2 3 1 | 5 9 7 | | 35 7 1-9 | 569 *89 58 | 234 126 246 | '--------------------------------------------------'

2. Y-wing (9=1)r1c3 - (1=8)r1c5 - (8=9)r9c5 => -9 r9c3; ste

Perhaps some loop solves the puzzle in one step (I did not find the right one).

by **SteveG48** » Sat Feb 18, 2023 2:51 pm

I kind of like that double Kraken.

by **Cenoman** » Sat Feb 18, 2023 3:06 pm

Code: Select all: +--------------------+----------------------+----------------------+ | 69 3 19 | 79 1789 278 | 247 5 246 | | 7 2 5 | 3 4 6 | 9 8 1 | | 8 a19-6* 4 | e579 1579 f257 | f27 f26 3 | +--------------------+----------------------+----------------------+ | 1 5 8 | 4 2 3 | 6 7 9 | | 369 a69* a39 | 1 57 57 | 28 4 28 | | 2 4 7 | 8 6 9 | 1 3 5 | +--------------------+----------------------+----------------------+ | 359 a19* 2 | d5679 5789 4 | 38 16 68 | | 4 8 6 | 2 3 1 | 5 9 7 | | 359 7 ba139* | d569 c589 c58 | 2348 126 2468 | +--------------------+----------------------+----------------------+

Almost ALS H-Wing [...Kraken cell (139)r9c3]:
[(1)r3c2 = r7c2 - (1=*3)r9c3 - (3=96)r5c23] = (9)r9c3 - (9=85)r9c56 - r79c4 = r3c4 - (5=276)r3c678 => -6r3c2: ste

by **P.O.** » Mon Feb 20, 2023 6:22 pm

thank you for your answers, i also find the double kraken by JCO very interesting, my solution:

Code: Select all: r1c3=1 - r9n1{c3 c8} - c8n2{r9 r3} - r3n6{c8 c2} - r5c2{n6 n9} - c3n9{r5 r9} - 58r9c56 r1c3=1 - r9n1{c3 c8} - c8n2{r9 r3} - r3c7{n2 n7} - r3c6{n27 n5} - r5n5{c6 c5} - b8n5{r79c5 r79c4} => r1c3 <> 1 ste.

by **yzfwsf** » Wed Mar 01, 2023 12:22 am

Just to test the new features of my solver(list all minimal puzzle).
The highest skfr rating minimal puzzle(9.0/1.2/1.2) :

Code: Select all: .3.....5.7......818.4.....3.5..236.9...1...4....8...35..2..4.....62315...7.......

The lowest skfr rating minimal puzzle(7.0/1.2/1.2) :

Code: Select all: .3.....5......69.18.4.....3.5....6.....1...4....8.913...2..4.....62315.7.7.......

by **ghfick** » Wed Mar 01, 2023 4:24 pm

I decided to explore puzzle 101 using the new YZF_Sudoku too.
There are 42,703 minimal puzzles from puzzle 101. Here is the frequency distribution of the number of givens:

Code: Select all: ----------------------- givens | ----------+----------- 24 | 36 25 | 715 26 | 4,676 27 | 12,222 28 | 13,511 29 | 8,137 30 | 2,936 31 | 457 32 | 13 -----------------------

Here is the frequency distribution of the SE ratings:

Code: Select all: ------------------------------------ SE | ---------------+------------------- ED=7.1/1.2/1.2 | 27,357 ED=7.1/1.5/1.5 | 1,222 ED=7.1/2.0/2.0 | 156 ED=7.1/2.3/2.3 | 20 ED=7.1/7.1/2.6 | 1 ED=7.2/1.2/1.2 | 9,020 ED=7.2/1.5/1.5 | 343 ED=7.2/2.0/2.0 | 22 ED=7.2/2.3/2.3 | 3 ED=7.3/1.2/1.2 | 2,406 ED=7.3/1.5/1.5 | 72 ED=7.3/2.0/2.0 | 12 ED=7.3/2.3/2.3 | 3 ED=7.4/1.2/1.2 | 220 ED=7.4/1.5/1.5 | 11 ED=7.4/2.0/2.0 | 3 ED=7.5/1.2/1.2 | 18 ED=7.5/2.0/2.0 | 1 ED=7.6/1.2/1.2 | 23 ED=7.7/1.2/1.2 | 11 ED=7.7/1.5/1.5 | 1 ED=7.8/1.2/1.2 | 74 ED=7.8/1.5/1.5 | 2 ED=7.9/1.2/1.2 | 10 ED=8.2/1.2/1.2 | 68 ED=8.2/2.0/2.0 | 3 ED=8.3/1.2/1.2 | 934 ED=8.3/1.5/1.5 | 49 ED=8.3/2.0/2.0 | 10 ED=8.3/2.3/2.3 | 3 ED=8.4/1.2/1.2 | 479 ED=8.4/1.5/1.5 | 10 ED=8.4/2.0/2.0 | 3 ED=8.5/1.2/1.2 | 93 ED=8.5/2.0/2.0 | 1 ED=8.5/7.1/2.6 | 1 ED=8.6/1.2/1.2 | 8 ED=8.7/1.2/1.2 | 4 ED=8.8/1.2/1.2 | 2 ED=8.9/1.2/1.2 | 15 ED=9.0/1.2/1.2 | 8 ED=9.1/1.2/1.2 | 1 -----------------------------------

Here is a table of both givens and SE:

Code: Select all: ------------------------------------------------------------------------------ | givens SE | 24 25 26 27 28 29 30 31 32 ---------------+-------------------------------------------------------------- ED=7.1/1.2/1.2 | 31 535 2,906 7,658 8,635 5,280 1,996 306 10 ED=7.1/1.5/1.5 | 39 198 205 404 292 72 12 ED=7.1/2.0/2.0 | 18 17 44 51 20 6 ED=7.1/2.3/2.3 | 4 8 4 4 ED=7.1/7.1/2.6 | 1 ED=7.2/1.2/1.2 | 1 65 861 3,048 3,211 1,377 392 63 2 ED=7.2/1.5/1.5 | 10 75 148 100 6 4 ED=7.2/2.0/2.0 | 5 12 5 ED=7.2/2.3/2.3 | 1 1 1 ED=7.3/1.2/1.2 | 1 17 295 469 578 683 325 38 ED=7.3/1.5/1.5 | 1 18 11 31 10 1 ED=7.3/2.0/2.0 | 1 4 3 1 1 2 ED=7.3/2.3/2.3 | 1 1 1 ED=7.4/1.2/1.2 | 11 73 54 24 37 11 10 ED=7.4/1.5/1.5 | 2 5 4 ED=7.4/2.0/2.0 | 3 ED=7.5/1.2/1.2 | 1 3 7 7 ED=7.5/2.0/2.0 | 1 ED=7.6/1.2/1.2 | 4 6 8 3 2 ED=7.7/1.2/1.2 | 3 1 3 1 3 ED=7.7/1.5/1.5 | 1 ED=7.8/1.2/1.2 | 31 4 24 15 ED=7.8/1.5/1.5 | 2 ED=7.9/1.2/1.2 | 3 2 4 1 ED=8.2/1.2/1.2 | 22 7 22 16 1 ED=8.2/2.0/2.0 | 2 1 ED=8.3/1.2/1.2 | 3 18 201 397 195 85 34 1 ED=8.3/1.5/1.5 | 2 6 25 13 3 ED=8.3/2.0/2.0 | 3 2 5 ED=8.3/2.3/2.3 | 1 2 ED=8.4/1.2/1.2 | 5 45 141 125 98 49 15 1 ED=8.4/1.5/1.5 | 3 4 1 2 ED=8.4/2.0/2.0 | 1 2 ED=8.5/1.2/1.2 | 5 20 16 20 29 3 ED=8.5/2.0/2.0 | 1 ED=8.5/7.1/2.6 | 1 ED=8.6/1.2/1.2 | 4 4 ED=8.7/1.2/1.2 | 3 1 ED=8.8/1.2/1.2 | 1 1 ED=8.9/1.2/1.2 | 5 5 1 4 ED=9.0/1.2/1.2 | 4 1 3 ED=9.1/1.2/1.2 | 1 ---------------------------------------------------------------------------------

Maybe the most unusual puzzle is:
.3.....5.7.....9818.4.....31...23.79...1...4.2..8.91.5..2..4...48.2.1.97.7....... ED=8.5/7.1/2.6

My elderly Mac took a while to create the list. YZF advises you of such. No matter. My Mac needed a little workout.

by **P.O.** » Wed Mar 01, 2023 6:51 pm

interesting analysis.
to get the puzzle i started with the pattern

Code: Select all: ......... 000000000 ......... 000000000 ......... 000000000 ......... 000000000 .........

while avoiding all basics at the beginning i got this puzzle with 19716 solutions

Code: Select all: ......... 725346981 ......... 158423679 ......... 247869135 ......... 486231597 .........

then i added clues until i got a single solution always checking that there were no basics and then checking the difficulty
all the first 36 clues are redundant, none of the 10 added clues are

Code: Select all: .3.....5. ......... 8.4.....3 ......... ...1...4. ......... ..2..4... ......... .7.......

The New Sudoku Players' Forum

Puzzle 101

Puzzle 101

Re: Puzzle 101

Re: Puzzle 101

Re: Puzzle 101

Re: Puzzle 101

Re: Puzzle 101

Re: Puzzle 101

Re: Puzzle 101

Re: Puzzle 101