The New Sudoku Players' Forum

[mith]

Code: Select all

+-------+-------+-------+
| 9 . . | . . 8 | 7 6 . |
| . . . | 1 9 . | . . . |
| . . 2 | . . . | . . . |
+-------+-------+-------+
| . 3 . | . . . | . . . |
| . 9 . | . . . | . 1 6 |
| 8 . . | . . . | 5 9 . |
+-------+-------+-------+
| 7 . . | . . 6 | 8 5 . |
| 5 . . | . 8 9 | 6 7 . |
| . . . | . 5 . | . . 4 |
+-------+-------+-------+
9....876....19......2.......3........9.....168.....59.7....685.5...8967.....5...4

[denis_berthier]

.
Solution using only Subsets and Finned-Fish

Resolution state after Singles and whips[1]:

Code: Select all

   +----------------------+----------------------+----------------------+
   ! 9      145    134    ! 2345   234    8      ! 7      6      1235   !
   ! 34     4578   34678  ! 1      9      2347   ! 234    2348   2358   !
   ! 1346   145678 2      ! 34567  3467   347    ! 1349   348    13589  !
   +----------------------+----------------------+----------------------+
   ! 1246   3      14567  ! 9      12467  12457  ! 24     248    278    !
   ! 24     9      457    ! 8      2347   23457  ! 234    1      6      !
   ! 8      12467  1467   ! 23467  123467 12347  ! 5      9      237    !
   +----------------------+----------------------+----------------------+
   ! 7      124    1349   ! 234    1234   6      ! 8      5      1239   !
   ! 5      124    134    ! 234    8      9      ! 6      7      123    !
   ! 1236   1268   13689  ! 237    5      1237   ! 1239   23     4      !
   +----------------------+----------------------+----------------------+

hidden-pairs-in-a-column: c7{n1 n9}{r3 r9} ==> r9c7 ≠ 3, r9c7 ≠ 2, r3c7 ≠ 4, r3c7 ≠ 3
finned-swordfish-in-columns: n1{c7 c1 c6}{r9 r3 r4} ==> r4c5 ≠ 1
finned-jellyfish-in-columns: n3{c8 c1 c7 c6}{r9 r3 r2 r5} ==> r5c5 ≠ 3
finned-jellyfish-in-rows: n2{r8 r7 r1 r6}{c9 c2 c5 c4} ==> r5c5 ≠ 2, r4c5 ≠ 2
finned-jellyfish-in-rows: n4{r8 r7 r1 r6}{c3 c2 c5 c4} ==> r5c5 ≠ 4, r4c5 ≠ 4
singles ==> r5c5 = 7, r4c5 = 6, r3c4 = 6, r1c4 = 5, r9c4 = 7
naked-triplets-in-a-block: b1{r1c2 r1c3 r3c1}{n1 n4 n3} ==> r3c2 ≠ 4, r3c2 ≠ 1, r2c3 ≠ 4, r2c3 ≠ 3, r2c2 ≠ 4, r2c1 ≠ 4, r2c1 ≠ 3
naked-single ==> r2c1 = 6
hidden-pairs-in-a-block: b7{n6 n8}{r9c2 r9c3} ==> r9c3 ≠ 9, r9c3 ≠ 3, r9c3 ≠ 1, r9c2 ≠ 2, r9c2 ≠ 1
stte

[mith]

Yep, that's exactly the intended path. A cleaner version of last week's finned puzzle.

There are some interesting MSLS/SET things that can be done as well (which ultimately amount to a multi-finned-fish).