The New Sudoku Players' Forum

[International_DBA]

I haven't posted here for a while.
This is quite extreme:
https://andrewspuzzles.blogspot.com/2022/12/sudoku-no-686-extreme.html

[storm_norm22]

this is the grid after some singles...
in case anyone wanted to copy it.

Code: Select all

+--------------------+----------------------+--------------------+
| 4579   579    1    | 4567   4678   2      | 4678  4689   3     |
| 2347   8      267  | 3467   1      9      | 5     46     67    |
| 34579  3579   5679 | 34567  34678  345678 | 2     1      6789  |
+--------------------+----------------------+--------------------+
| 127    4      27   | 8      5      1367   | 9     236    126   |
| 6      1257   3    | 47     9      147    | 48    248    1258  |
| 8      159    59   | 2      346    1346   | 346   7      156   |
+--------------------+----------------------+--------------------+
| 23579  6      8    | 34579  347    3457   | 1     239    279   |
| 23579  23579  4    | 1      3678   35678  | 3678  23689  26789 |
| 1379   1379   79   | 3679   2      3678   | 3678  5      4     |
+--------------------+----------------------+--------------------+




original string
001000003080009500000000210040850900603090000000200070068000100004100000000020054

[eleven]

Just to give an answer.
After 3 steps, 2 of them complex, i had 3 numbers, but the ER just lowered from 9.1 to 9.0 - and i still could not find any interesting move.
Didn't want to waste more time on it ...

[denis_berthier]

.
This is a typical SER 9.1 puzzle, except that its number of candidates is not typical.

Code: Select all

Resolution state after Singles and whips[1]:
   +----------------------+----------------------+----------------------+
   ! 4579   579    1      ! 4567   4678   2      ! 4678   4689   3      !
   ! 2347   8      267    ! 3467   1      9      ! 5      46     67     !
   ! 34579  3579   5679   ! 34567  34678  345678 ! 2      1      6789   !
   +----------------------+----------------------+----------------------+
   ! 127    4      27     ! 8      5      1367   ! 9      236    126    !
   ! 6      1257   3      ! 47     9      147    ! 48     248    1258   !
   ! 8      159    59     ! 2      346    1346   ! 346    7      156    !
   +----------------------+----------------------+----------------------+
   ! 23579  6      8      ! 34579  347    3457   ! 1      239    279    !
   ! 23579  23579  4      ! 1      3678   35678  ! 3678   23689  26789  !
   ! 1379   1379   79     ! 3679   2      3678   ! 3678   5      4      !
   +----------------------+----------------------+----------------------+
200 candidates.
183 g-candidates, 944 csp-glinks and 551 non-csp glinks

It has a solution in W10 or in gW10. Here's the one in gW10, also typical of a 9.1 puzzle. If you're used to see shorter resolution paths, it's mainly because puzzles proposed here are filtered and do not reflect the reality of randomly chosen puzzles.

Code: Select all

biv-chain[3]: r9c3{n9 n7} - r4c3{n7 n2} - c2n2{r5 r8} ==> r8c2≠9
biv-chain[5]: r2n3{c4 c1} - b1n2{r2c1 r2c3} - r4c3{n2 n7} - r9c3{n7 n9} - b8n9{r9c4 r7c4} ==> r7c4≠3
t-whip[4]: c4n3{r3 r9} - r2n3{c4 c1} - r7n3{c1 c8} - r4n3{c8 .} ==> r3c6≠3
g-whip[5]: r5c4{n7 n4} - r6n4{c6 c7} - b6n3{r6c7 r4c8} - b6n6{r4c8 r456c9} - r2c9{n6 .} ==> r2c4≠7
t-whip[6]: r2c9{n7 n6} - c3n6{r2 r3} - c3n5{r3 r6} - r6c9{n5 n1} - r4c9{n1 n2} - r4c3{n2 .} ==> r2c3≠7
t-whip[7]: r5c4{n7 n4} - r5c7{n4 n8} - r5c8{n8 n2} - b6n4{r5c8 r6c7} - b6n3{r6c7 r4c8} - r7c8{n3 n9} - c4n9{r7 .} ==> r9c4≠7
whip[7]: c2n2{r8 r5} - r5n5{c2 c9} - c9n8{r5 r3} - b3n9{r3c9 r1c8} - r8n9{c8 c1} - r9c3{n9 n7} - r4c3{n7 .} ==> r8c9≠2
whip[8]: r2c9{n7 n6} - c3n6{r2 r3} - c3n5{r3 r6} - c3n9{r6 r9} - c4n9{r9 r7} - c9n9{r7 r3} - c9n8{r3 r5} - r5n5{c9 .} ==> r8c9≠7
whip[8]: r2c9{n7 n6} - c3n6{r2 r3} - c3n5{r3 r6} - c3n9{r6 r9} - c4n9{r9 r7} - c9n9{r7 r8} - c9n8{r8 r5} - r5n5{c9 .} ==> r3c9≠7
t-whip[10]: r5c4{n7 n4} - r5c7{n4 n8} - r5c8{n8 n2} - b6n4{r5c8 r6c7} - b6n3{r6c7 r4c8} - r7c8{n3 n9} - r8n9{c9 c1} - r8n2{c1 c2} - r8n5{c2 c6} - r7c4{n5 .} ==> r1c4≠7, r3c4≠7
whip[9]: r9c3{n9 n7} - r4c3{n7 n2} - r2n2{c3 c1} - r2n3{c1 c4} - r9c4{n3 n6} - c4n9{r9 r7} - c4n7{r7 r5} - b4n7{r5c2 r4c1} - c1n1{r4 .} ==> r9c1≠9
g-whip[9]: b7n5{r8c1 r8c2} - c2n2{r8 r5} - r4c3{n2 n7} - r9c3{n7 n9} - c1n9{r8 r3} - r3n4{c1 c456} - r1c4{n4 n6} - r9c4{n6 n3} - r2c4{n3 .} ==> r1c1≠5
whip[10]: r4n6{c9 c6} - r4n3{c6 c8} - r6c7{n3 n4} - r5c7{n4 n8} - r5c8{n8 n2} - r7c8{n2 n9} - r8c9{n9 n8} - r8c8{n8 n6} - r9n6{c7 c4} - c4n9{r9 .} ==> r6c9≠6
naked-triplets-in-a-row: r6{c2 c3 c9}{n1 n9 n5} ==> r6c6≠1
whip[10]: r4c3{n2 n7} - r9c3{n7 n9} - r6c3{n9 n5} - r5n5{c2 c9} - r5n2{c9 c8} - r5c2{n2 n1} - c6n1{r5 r4} - r4n3{c6 c8} - r7c8{n3 n9} - c4n9{r7 .} ==> r4c1≠2
whip[8]: r9n8{c7 c6} - r9n6{c6 c4} - c4n9{r9 r7} - r7c8{n9 n2} - r7c9{n2 n7} - r2n7{c9 c1} - r4c1{n7 n1} - r9c1{n1 .} ==> r9c7≠3
biv-chain[2]: c7n3{r8 r6} - r4n3{c8 c6} ==> r8c6≠3
z-chain[4]: r2n3{c1 c4} - r9n3{c4 c6} - r4n3{c6 c8} - b9n3{r7c8 .} ==> r8c1≠3
t-whip[6]: c4n7{r5 r7} - c4n9{r7 r9} - r9c3{n9 n7} - b9n7{r9c7 r8c7} - c7n3{r8 r6} - b5n3{r6c5 .} ==> r4c6≠7
whip[1]: b5n7{r5c6 .} ==> r5c2≠7
whip[6]: c4n7{r5 r7} - c4n9{r7 r9} - r9c3{n9 n7} - b9n7{r9c7 r8c7} - c7n3{r8 r6} - r6n4{c7 .} ==> r5c4≠4
naked-single ==> r5c4=7
whip[6]: c4n4{r3 r7} - c4n9{r7 r9} - r9c3{n9 n7} - r4n7{c3 c1} - r1c1{n7 n9} - b7n9{r7c1 .} ==> r1c5≠4
whip[6]: b4n7{r4c1 r4c3} - b4n2{r4c3 r5c2} - r8n2{c2 c8} - r8n9{c8 c9} - r7c9{n9 n7} - r2n7{c9 .} ==> r8c1≠7
whip[8]: r2n3{c4 c1} - r2n2{c1 c3} - r4c3{n2 n7} - r4c1{n7 n1} - r9n1{c1 c2} - r9n3{c2 c6} - r7n3{c5 c8} - r4n3{c8 .} ==> r3c4≠3
g-whip[8]: c2n7{r3 r789} - r9c3{n7 n9} - c4n9{r9 r7} - c4n4{r7 r123} - r3n4{c5 c4} - c4n5{r3 r1} - r1c2{n5 n9} - r6n9{c2 .} ==> r3c1≠7
g-whip[8]: b4n7{r4c1 r4c3} - r9c3{n7 n9} - c4n9{r9 r7} - c1n9{r7 r3} - r3n4{c1 c456} - c4n4{r1 r3} - c4n5{r3 r1} - r1c2{n5 .} ==> r1c1≠7
t-whip[9]: c9n5{r5 r6} - r6c3{n5 n9} - r9c3{n9 n7} - b4n7{r4c3 r4c1} - r2n7{c1 c9} - b9n7{r7c9 r8c7} - c7n3{r8 r6} - b5n3{r6c5 r4c6} - r4n1{c6 .} ==> r5c9≠1
t-whip[9]: r9c3{n9 n7} - b4n7{r4c3 r4c1} - r2n7{c1 c9} - b9n7{r7c9 r8c7} - c7n3{r8 r6} - b5n3{r6c5 r4c6} - r4n1{c6 c9} - r6n1{c9 c2} - r6n9{c2 .} ==> r3c3≠9
biv-chain[4]: r1n5{c4 c2} - c3n5{r3 r6} - c3n9{r6 r9} - b8n9{r9c4 r7c4} ==> r7c4≠5
whip[1]: b8n5{r8c6 .} ==> r3c6≠5
t-whip[9]: r6c3{n5 n9} - r9c3{n9 n7} - b4n7{r4c3 r4c1} - r2n7{c1 c9} - b9n7{r7c9 r8c7} - c7n3{r8 r6} - b5n3{r6c5 r4c6} - c6n1{r4 r5} - b4n1{r5c2 .} ==> r6c2≠5
whip[8]: r5c7{n4 n8} - r5c8{n8 n2} - r5c9{n2 n5} - r6n5{c9 c3} - c3n9{r6 r9} - c4n9{r9 r7} - r7c8{n9 n3} - b6n3{r4c8 .} ==> r6c7≠4
whip[1]: r6n4{c6 .} ==> r5c6≠4
naked-single ==> r5c6=1
biv-chain[3]: r4c3{n7 n2} - r5c2{n2 n5} - c3n5{r6 r3} ==> r3c3≠7
biv-chain[3]: c3n7{r9 r4} - r4c1{n7 n1} - b7n1{r9c1 r9c2} ==> r9c2≠7
g-whip[7]: r9n8{c6 c7} - r9n7{c7 c123} - c2n7{r8 r123} - r2n7{c1 c9} - b9n7{r7c9 r8c7} - c7n3{r8 r6} - b5n3{r6c5 .} ==> r9c6≠3
finned-x-wing-in-rows: n3{r2 r9}{c4 c1} ==> r7c1≠3
z-chain[5]: r6n9{c2 c3} - b4n5{r6c3 r5c2} - c2n2{r5 r8} - b7n3{r8c2 r9c1} - r9n1{c1 .} ==> r9c2≠9
z-chain[4]: r3c3{n6 n5} - r6c3{n5 n9} - r9n9{c3 c4} - c4n6{r9 .} ==> r3c6≠6, r3c5≠6
t-whip[5]: r3c3{n6 n5} - r6c3{n5 n9} - r9n9{c3 c4} - r7c4{n9 n4} - r3c4{n4 .} ==> r3c9≠6
whip[8]: b2n7{r3c5 r3c6} - c2n7{r3 r1} - c7n7{r1 r9} - r9n8{c7 c6} - r9n6{c6 c4} - r8c6{n6 n5} - b7n5{r8c1 r7c1} - r7n7{c1 .} ==> r8c5≠7
whip[7]: r9n8{c7 c6} - r9n6{c6 c4} - b2n6{r3c4 r1c5} - r1n7{c5 c2} - b7n7{r8c2 r7c1} - c5n7{r7 r3} - c5n8{r3 .} ==> r9c7≠7
finned-swordfish-in-columns: n7{c2 c7 c5}{r3 r1 r8} ==> r8c6≠7
t-whip[3]: b9n7{r8c7 r7c9} - b8n7{r7c6 r9c6} - r9n8{c6 .} ==> r8c7≠8
whip[7]: c4n6{r3 r9} - r9c7{n6 n8} - r1n8{c7 c8} - r5n8{c8 c9} - r5n5{c9 c2} - c3n5{r6 r3} - r3n6{c3 .} ==> r1c5≠6
whip[1]: b2n6{r3c4 .} ==> r9c4≠6
hidden-pairs-in-a-row: r9{n6 n8}{c6 c7} ==> r9c6≠7
whip[1]: r9n7{c3 .} ==> r7c1≠7, r8c2≠7
singles ==> r8c7=7, r2c9=7, r6c7=3, r4c6=3
hidden-pairs-in-a-column: c1{n1 n7}{r4 r9} ==> r9c1≠3
whip[1]: b7n3{r9c2 .} ==> r3c2≠3
biv-chain[4]: b4n5{r5c2 r6c3} - c3n9{r6 r9} - r9c4{n9 n3} - b7n3{r9c2 r8c2} ==> r8c2≠5
whip[1]: b7n5{r8c1 .} ==> r3c1≠5
t-whip[3]: r7c9{n2 n9} - r8n9{c9 c1} - c1n5{r8 .} ==> r7c1≠2
whip[1]: r7n2{c9 .} ==> r8c8≠2
biv-chain[4]: c1n2{r2 r8} - r8c2{n2 n3} - r9n3{c2 c4} - r2n3{c4 c1} ==> r2c1≠4
biv-chain[4]: r7n2{c9 c8} - b9n3{r7c8 r8c8} - r8c2{n3 n2} - b4n2{r5c2 r4c3} ==> r4c9≠2
biv-chain[5]: c9n6{r8 r4} - r4c8{n6 n2} - b4n2{r4c3 r5c2} - r8n2{c2 c1} - r8n5{c1 c6} ==> r8c6≠6
whip[6]: r9c7{n8 n6} - r8c9{n6 n9} - b3n9{r3c9 r1c8} - r1c1{n9 n4} - r1c7{n4 n8} - r3c9{n8 .} ==> r8c8≠8
t-whip[5]: r7n7{c6 c5} - r1c5{n7 n8} - b3n8{r1c7 r3c9} - r8n8{c9 c6} - c6n5{r8 .} ==> r7c6≠4
biv-chain[4]: c7n6{r1 r9} - c6n6{r9 r6} - c6n4{r6 r3} - b1n4{r3c1 r1c1} ==> r1c7≠4
hidden-single-in-a-column ==> r5c7=4
biv-chain[4]: c7n6{r1 r9} - c6n6{r9 r6} - c6n4{r6 r3} - r2n4{c4 c8} ==> r2c8≠6
naked-single ==> r2c8=4
whip[1]: b3n6{r1c8 .} ==> r1c4≠6
t-whip[5]: r1c5{n7 n8} - r1c7{n8 n6} - r9n6{c7 c6} - r6c6{n6 n4} - r3c6{n4 .} ==> r3c5≠7
biv-chain[5]: r3n7{c2 c6} - r7c6{n7 n5} - r7c1{n5 n9} - c3n9{r9 r6} - b4n5{r6c3 r5c2} ==> r3c2≠5
hidden-pairs-in-a-row: r3{n5 n6}{c3 c4} ==> r3c4≠4
z-chain[4]: b7n9{r8c1 r9c3} - c4n9{r9 r7} - c4n4{r7 r1} - r1c1{n4 .} ==> r3c1≠9
biv-chain[4]: r3n9{c9 c2} - r3n7{c2 c6} - r7c6{n7 n5} - r7c1{n5 n9} ==> r7c9≠9
naked-single ==> r7c9=2
biv-chain[4]: c2n7{r3 r1} - c2n5{r1 r5} - r5c9{n5 n8} - r3c9{n8 n9} ==> r3c2≠9
singles ==> r3c2=7, r1c5=7, r7c6=7, r8c6=5, r7c1=5, r3c9=9
naked-pairs-in-a-block: b9{r8c9 r9c7}{n6 n8} ==> r8c8≠6
hidden-pairs-in-a-row: r8{n6 n8}{c5 c9} ==> r8c5≠3
biv-chain[5]: b9n8{r9c7 r8c9} - r5c9{n8 n5} - c2n5{r5 r1} - r1c4{n5 n4} - r3c6{n4 n8} ==> r9c6≠8
stte