.
- Code: Select all
Resolution state after Singles and whips[1]:
+----------------------+----------------------+----------------------+
! 5 4 1238 ! 278 278 278 ! 12378 6 9 !
! 7 369 2389 ! 1 24689 2689 ! 238 48 5 !
! 1269 169 1289 ! 245678 3 256789 ! 1278 1478 1247 !
+----------------------+----------------------+----------------------+
! 139 2 7 ! 3568 168 4 ! 15689 1589 13 !
! 139 13589 6 ! 23578 1278 23578 ! 4 15789 137 !
! 13 1358 4 ! 9 1678 35678 ! 15678 2 137 !
+----------------------+----------------------+----------------------+
! 12369 1369 1239 ! 23478 5 23789 ! 1279 1479 1247 !
! 8 39 2359 ! 2347 2479 1 ! 2579 4579 6 !
! 4 7 1259 ! 26 269 269 ! 1259 3 8 !
+----------------------+----------------------+----------------------+
221 candidates.
Notice that this is a lot of candidates, so that we might expect the puzzle to be hard. But we know that the increasing relation between SER and the number of candidates is only statistical and it has a very large variance.
Indeed, SER = 4.2 and the puzzle can be solved in BC3, using the simplest first strategy:
- Code: Select all
hidden-pairs-in-a-row: r9{n1 n5}{c3 c7} ==> r9c7≠9, r9c7≠2, r9c3≠9, r9c3≠2
whip[1]: r9n2{c6 .} ==> r7c4≠2, r7c6≠2, r8c4≠2, r8c5≠2
whip[1]: r9n9{c6 .} ==> r7c6≠9, r8c5≠9
hidden-pairs-in-a-column: c2{n5 n8}{r5 r6} ==> r6c2≠3, r6c2≠1, r5c2≠9, r5c2≠3, r5c2≠1
whip[1]: b4n1{r6c1 .} ==> r3c1≠1, r7c1≠1
whip[1]: b4n3{r6c1 .} ==> r7c1≠3
whip[1]: b4n9{r5c1 .} ==> r3c1≠9, r7c1≠9
hidden-pairs-in-a-column: c9{n2 n4}{r3 r7} ==> r7c9≠7, r7c9≠1, r3c9≠7, r3c9≠1
whip[1]: c9n1{r6 .} ==> r4c7≠1, r4c8≠1, r5c8≠1, r6c7≠1
whip[1]: c9n7{r6 .} ==> r5c8≠7, r6c7≠7
hidden-pairs-in-a-row: r1{n1 n3}{c3 c7} ==> r1c7≠8, r1c7≠7, r1c7≠2, r1c3≠8, r1c3≠2
whip[1]: r1n2{c6 .} ==> r2c5≠2, r2c6≠2, r3c4≠2, r3c6≠2
whip[1]: r1n8{c6 .} ==> r2c5≠8, r2c6≠8, r3c4≠8, r3c6≠8
whip[1]: b3n7{r3c8 .} ==> r3c4≠7, r3c6≠7
x-wing-in-columns: n1{c2 c8}{r3 r7} ==> r7c7≠1, r7c3≠1, r3c7≠1, r3c3≠1
x-wing-in-columns: n2{c1 c9}{r3 r7} ==> r7c7≠2, r7c3≠2, r3c7≠2, r3c3≠2
naked-pairs-in-a-block: b7{r7c3 r8c2}{n3 n9} ==> r8c3≠9, r8c3≠3, r7c2≠9, r7c2≠3
biv-chain[3]: r2c8{n8 n4} - r3c9{n4 n2} - b1n2{r3c1 r2c3} ==> r2c3≠8
stte
which is 1-step for people who consider Subsets[2] as "basics".