The New Sudoku Players' Forum

[urhegyi]

challange.png (14.16 KiB) Viewed 524 times

[SpAce]

Code: Select all

1..2..3....4..5..6.8.......2..3..1....5.....4.9...8...3..1..2....6..4..5....8....

Code: Select all

.-----------------.--------------------.--------------------.
| 1      56   79  | 2     4679     679 | 3      45789   789 |
| 79     23   4   | 8     3-1      5   | 79    *12      6   |
| 56     8    23  | 4679  4679    *13  | 4579   4579    2-1 |
:-----------------+--------------------+--------------------:
| 2      467  78  | 3     45679    679 | 1      56789   789 |
| 678   *13   5   | 679   12679   *12  | 6789   236789  4   |
| 467    9    13  | 4567  124567   8   | 567    23567   23  |
:-----------------+--------------------+--------------------:
| 3      457  789 | 1     5679     679 | 2      46789   789 |
| 789   *12   6   | 79    23       4   | 789   *13      5   |
| 4579   457  12  | 5679  8        23  | 4679   4679    13  |
'-----------------'--------------------'--------------------'

Step 1. Big Skyscraper (aka Siamese Finned Sashimi Swordfish)

3x4 (1)c268\r58(r2b2|r3b3) => -1 r2c5,r3c9

Code: Select all

       \45    *79          \45      *79          \45      *79
.------------------.---------------------.---------------------.
| 1    ^56    *79  | 2     ^46-79   *679 | 3     ^458-79  *789 | ^45 \79
| 79    2      4   | 8      3        5   | 79     1        6   |
| 56    8      3   | 4679   679-4    1   | 4579   79-45    2   |
:------------------+---------------------+---------------------:
| 2    ^46-7  *78  | 3     ^456-79  *679 | 1     ^568-79  *789 | ^45 \79
| 678   3      5   | 679    1        2   | 6789   6789     4   |
| 467   9      1   | 4567   67-45    8   | 567    2        3   |
:------------------+---------------------+---------------------:
| 3    ^45-7  *789 | 1     ^56-79   *679 | 2     ^468-79  *789 | ^45 \79
| 789   1      6   | 79     2        4   | 789    3        5   |
| 4579  7-45   2   | 5679   8        3   | 4679   679-4    1   |
'------------------'---------------------'---------------------'

Step 2. Four packed Swordfishes

12x12 {45R147 79C369 \ 45c258 79r147} => -4r3c5,r9c8; -45r9c2,r6c5,r3c8; -7r47c2, -79r147c58; stte

[pjb]

Fun puzzle! Fish galor. One of many choices:

Starfish of 7s (r23568\c14578) => 10 elims
(Naked pairs of 89)
Starfish of 9s (r23589\c14578) => 3 elims
(Naked triplets of 456)
(Naked quins of 12679)
X-wing of 8s (c17\r58)
Finned swordfish of 1s (r258\c258), fin at r5c6
(Naked pairs of 46)
Finned X-wing of 7s (r83\c47), fin at r3c8 => solved

Phil

[Cenoman]

5-fish solution (in any sequence):

Code: Select all

 +---------------------+------------------------+------------------------+
 |  1      56#   79^   |  2      46-79#   679^  |  3      458-79#  789^  |
 |  79     23    4     |  8      13*      5     |  79     12*      6     |
 |  56     8     23    |  4679   679-4    13    |  4579   79-45    12    |
 +---------------------+------------------------+------------------------+
 |  2      46-7# 78^   |  3      456-79#  679^  |  1      568-79#  789^  |
 |  678    13*   5     |  679    12679*   12*   |  6789   236789   4     |
 |  467    9     13    |  4567   267-145  8     |  567    2367-5   23    |
 +---------------------+------------------------+------------------------+
 |  3      45-7# 789^  |  1      56-79#   679^  |  2      468-79#  789^  |
 |  789    12*   6     |  79     23       4     |  789    13*      5     |
 |  4579   7-45  12    |  5679   8        23    |  4679   679-4    13    |
 +---------------------+------------------------+------------------------+

Finned swordfish * (1)r258\c258 + fin 1r5c6 => -1 r6c5; 18 placements & basics
Swordfishes ^ (7)&(9)c369\r147 => -79r147c69, -7r47c2; 1 placement & basics
Swordfishes # (4)&(5)r147\c258 => -4 r3c58, r6c5, r9c2; -5 r3c8, r6c58, r9c2; 2 placements & basics
Singles to the end for the whole set of eliminations.

This 5-fish solution is presented as such in the context of the recent puzzles.
To me, the first fish eliminating 1r6c5 is better presented as a simple coloring (easier to spot than a finned SF):
(1)r5c56 = r5c2 - r8c2 = r8c8 - r2c8 = r2c5 => -1 r6c5 (other SC-chains yield the same result)
Note: the SF 4s and 5s can be written as X-loops...

[denis_berthier]

A small thing is needed addition to ordinary Subsets.

Hidden Text: Show

***********************************************************************************************
*** SudoRules 20.1.s based on CSP-Rules 2.1.s, config = Z+SFin
*** Using CLIPS 6.32-r770
***********************************************************************************************
hidden-single-in-a-column ==> r2c4 = 8
228 candidates, 1603 csp-links and 1603 links. Density = 6.19%
naked-pairs-in-a-row: r2{c1 c7}{n7 n9} ==> r2c8 ≠ 9, r2c8 ≠ 7, r2c5 ≠ 9, r2c5 ≠ 7, r2c2 ≠ 7
naked-pairs-in-a-block: b1{r1c3 r2c1}{n7 n9} ==> r3c3 ≠ 9, r3c3 ≠ 7, r3c1 ≠ 9, r3c1 ≠ 7, r1c2 ≠ 7
hidden-pairs-in-a-block: b8{r8c5 r9c6}{n2 n3} ==> r9c6 ≠ 9, r9c6 ≠ 7, r9c6 ≠ 6, r8c5 ≠ 9, r8c5 ≠ 7
hidden-pairs-in-a-block: b4{r5c2 r6c3}{n1 n3} ==> r6c3 ≠ 7, r5c2 ≠ 7, r5c2 ≠ 6
x-wing-in-columns: n8{c1 c7}{r5 r8} ==> r8c8 ≠ 8, r5c8 ≠ 8
naked-triplets-in-a-row: r8{c1 c4 c7}{n8 n9 n7} ==> r8c8 ≠ 9, r8c8 ≠ 7, r8c2 ≠ 7
naked-triplets-in-a-column: c2{r2 r5 r8}{n2 n3 n1} ==> r9c2 ≠ 2, r9c2 ≠ 1
hidden-pairs-in-a-block: b7{r8c2 r9c3}{n1 n2} ==> r9c3 ≠ 9, r9c3 ≠ 7
naked-triplets-in-a-column: c9{r1 r4 r7}{n9 n8 n7} ==> r9c9 ≠ 9, r9c9 ≠ 7, r6c9 ≠ 7, r3c9 ≠ 9, r3c9 ≠ 7
naked-pairs-in-a-block: b3{r2c8 r3c9}{n1 n2} ==> r3c8 ≠ 2, r3c8 ≠ 1
naked-pairs-in-a-block: b9{r8c8 r9c9}{n1 n3} ==> r9c8 ≠ 3, r9c8 ≠ 1
naked-triplets-in-a-column: c6{r1 r4 r7}{n9 n7 n6} ==> r5c6 ≠ 9, r5c6 ≠ 7, r5c6 ≠ 6, r3c6 ≠ 9, r3c6 ≠ 7, r3c6 ≠ 6
naked-pairs-in-a-block: b2{r2c5 r3c6}{n1 n3} ==> r3c5 ≠ 3, r3c5 ≠ 1
swordfish-in-columns: n4{c1 c4 c7}{r9 r6 r3} ==> r9c8 ≠ 4, r9c2 ≠ 4, r6c5 ≠ 4, r3c8 ≠ 4, r3c5 ≠ 4
swordfish-in-columns: n9{c3 c6 c9}{r7 r1 r4} ==> r7c8 ≠ 9, r7c5 ≠ 9, r4c8 ≠ 9, r4c5 ≠ 9, r1c8 ≠ 9, r1c5 ≠ 9
swordfish-in-columns: n7{c3 c6 c9}{r7 r4 r1} ==> r7c8 ≠ 7, r7c5 ≠ 7, r7c2 ≠ 7, r4c8 ≠ 7, r4c5 ≠ 7, r4c2 ≠ 7, r1c8 ≠ 7, r1c5 ≠ 7
hidden-single-in-a-column ==> r9c2 = 7
naked-pairs-in-a-block: b7{r7c3 r8c1}{n8 n9} ==> r9c1 ≠ 9
naked-triplets-in-a-column: c5{r1 r4 r7}{n6 n4 n5} ==> r6c5 ≠ 6, r6c5 ≠ 5, r5c5 ≠ 6, r3c5 ≠ 6
hidden-pairs-in-a-block: b5{r4c5 r6c4}{n4 n5} ==> r6c4 ≠ 7, r6c4 ≠ 6, r4c5 ≠ 6
swordfish-in-columns: n6{c2 c5 c6}{r4 r1 r7} ==> r7c8 ≠ 6, r4c8 ≠ 6
whip[1]: b9n6{r9c8 .} ==> r9c4 ≠ 6
naked-triplets-in-a-column: c8{r1 r4 r7}{n4 n5 n8} ==> r6c8 ≠ 5, r3c8 ≠ 5
naked-pairs-in-a-block: b3{r2c7 r3c8}{n7 n9} ==> r3c7 ≠ 9, r3c7 ≠ 7, r1c9 ≠ 9, r1c9 ≠ 7
naked-single ==> r1c9 = 8
naked-pairs-in-a-row: r3{c5 c8}{n7 n9} ==> r3c4 ≠ 9, r3c4 ≠ 7
naked-pairs-in-a-block: b2{r1c5 r3c4}{n4 n6} ==> r1c6 ≠ 6
biv-chain[2]: c5n9{r5 r3} - b3n9{r3c8 r2c7} ==> r5c7 ≠ 9
swordfish-in-columns: n3{c3 c6 c9}{r6 r3 r9} ==> r6c8 ≠ 3
finned-swordfish-in-columns: n1{c2 c8 c6}{r5 r8 r2} ==> r2c5 ≠ 1
stte

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