[Added for clarity of this thread]: This post marks a new turn in the use of the anti-tridagon pattern; see the post referenced below for the definition of new ORk-chains.
Using the OR-k-Forcing-Whips introduced here http://forum.enjoysudoku.com/or-k-forcing-whips-t40189.html,
here is a solution of min-expand #339, one of the puzzles that still has 4 guardians after applying W7.
- Code: Select all
+-------+-------+-------+
! . . . ! 4 . 6 ! 7 8 . !
! . . . ! . . . ! 2 . . !
! . 8 . ! 2 7 . ! . . . !
+-------+-------+-------+
! 2 . 8 ! 3 4 . ! . . 7 !
! 3 7 . ! . 6 . ! . . . !
! . 4 6 ! 8 . 7 ! . . . !
+-------+-------+-------+
! . 6 . ! . . . ! 1 9 4 !
! . 3 4 ! . . . ! 5 2 . !
! . . . ! . . 4 ! . 7 3 !
+-------+-------+-------+
...4.678.......2...8.27....2.834...737..6.....468.7....6....194.34...52......4.73;111;44367
- Code: Select all
Resolution state after Singles and whips[1]:
+----------------------+----------------------+----------------------+
! 159 1259 12359 ! 4 1359 6 ! 7 8 159 !
! 145679 159 13579 ! 159 13589 13589 ! 2 13456 1569 !
! 14569 8 1359 ! 2 7 1359 ! 3469 13456 1569 !
+----------------------+----------------------+----------------------+
! 2 159 8 ! 3 4 159 ! 69 156 7 !
! 3 7 159 ! 159 6 1259 ! 489 145 12589 !
! 159 4 6 ! 8 1259 7 ! 39 135 1259 !
+----------------------+----------------------+----------------------+
! 578 6 257 ! 57 2358 2358 ! 1 9 4 !
! 1789 3 4 ! 1679 189 189 ! 5 2 68 !
! 1589 1259 1259 ! 1569 12589 4 ! 68 7 3 !
+----------------------+----------------------+----------------------+
184 candidates
- Code: Select all
hidden-pairs-in-a-column: c1{n4 n6}{r2 r3} ==> r3c1≠9, r3c1≠5, r3c1≠1, r2c1≠9, r2c1≠7, r2c1≠5, r2c1≠1
hidden-single-in-a-block ==> r2c3=7
biv-chain[3]: r4c7{n9 n6} - b9n6{r9c7 r8c9} - c9n8{r8 r5} ==> r5c9≠9
z-chain[3]: c4n6{r9 r8} - r8n7{c4 c1} - r8n1{c1 .} ==> r9c4≠1
z-chain[3]: c4n6{r9 r8} - r8n7{c4 c1} - r8n9{c1 .} ==> r9c4≠9
biv-chain[4]: r4c7{n9 n6} - b9n6{r9c7 r8c9} - c9n8{r8 r5} - b6n2{r5c9 r6c9} ==> r6c9≠9
whip[1]: c9n9{r3 .} ==> r3c7≠9
biv-chain[4]: r8c9{n6 n8} - b6n8{r5c9 r5c7} - c7n4{r5 r3} - r3c1{n4 n6} ==> r3c9≠6
z-chain[5]: c1n7{r8 r7} - c1n8{r7 r9} - b9n8{r9c7 r8c9} - r8n6{c9 c4} - r8n7{c4 .} ==> r8c1≠1, r8c1≠9
whip[1]: r8n9{c6 .} ==> r9c5≠9
whip[1]: r8n1{c6 .} ==> r9c5≠1
+-------------------+-------------------+-------------------+
! 159 1259 12359 ! 4 1359 6 ! 7 8 159 !
! 46 159 7 ! 159 13589 13589 ! 2 13456 1569 !
! 46 8 1359 ! 2 7 1359 ! 346 13456 159 !
+-------------------+-------------------+-------------------+
! 2 159 8 ! 3 4 159 ! 69 156 7 !
! 3 7 159 ! 159 6 1259 ! 489 145 1258 !
! 159 4 6 ! 8 1259 7 ! 39 135 125 !
+-------------------+-------------------+-------------------+
! 578 6 25 ! 57 2358 2358 ! 1 9 4 !
! 78 3 4 ! 1679 189 189 ! 5 2 68 !
! 1589 1259 1259 ! 56 258 4 ! 68 7 3 !
+-------------------+-------------------+-------------------+
OR4-anti-tridagon[12] (type diag) for digits 1, 5 and 9 in blocks:
b1, with cells: r1c1, r2c2, r3c3
b2, with cells: r1c5, r2c4, r3c6
b4, with cells: r6c1, r4c2, r5c3
b5, with cells: r6c5, r4c6, r5c4
with 4 guardians: n3r1c5 n3r3c3 n3r3c6 n2r6c5
Based on this OR4 relation, several OR4-Forcing-Whips will allow an easy solution.
- Code: Select all
OR4-forcing-whip-elim[4] based on OR4-anti-tridagon[12] for n3r3c6, n3r1c5, n3r3c3 and n2r6c5:
|| n3r3c6 -
|| n3r1c5 -
|| n3r3c3 - partial-whip[1]: b3n3{r3c8 r2c8} -
|| n2r6c5 - partial-whip[2]: c6n2{r5 r7} - r7n3{c6 c5} -
==> r2c5≠3
t-whip[5]: c6n8{r8 r2} - r2n3{c6 c8} - r2n4{c8 c1} - r2n6{c1 c9} - r8c9{n6 .} ==> r8c5≠8
OR4-forcing-whip-elim[5] based on OR4-anti-tridagon[12] for n3r3c6, n3r3c3, n3r1c5 and n2r6c5:
|| n3r3c6 -
|| n3r3c3 -
|| n3r1c5 - partial-whip[1]: c3n3{r1 r3} -
|| n2r6c5 - partial-whip[3]: r5n2{c6 c9} - r5n8{c9 c7} - c7n4{r5 r3} -
==> r3c7≠3
hidden-single-in-a-column ==> r6c7=3
naked-pairs-in-a-row: r3{c1 c7}{n4 n6} ==> r3c8≠6, r3c8≠4
z-chain[5]: c6n2{r5 r7} - r7c3{n2 n5} - r5c3{n5 n9} - r6n9{c1 c5} - b5n2{r6c5 .} ==> r5c6≠1
t-whip[6]: c5n3{r7 r1} - r2n3{c6 c8} - r2n4{c8 c1} - r2n6{c1 c9} - r8n6{c9 c4} - r9c4{n6 .} ==> r7c5≠5
OR4-forcing-whip-elim[7] based on OR4-anti-tridagon[12] for n3r3c6, n3r3c3, n3r1c5 and n2r6c5:
|| n3r3c6 - partial-whip[1]: r2n3{c6 c8} -
|| n3r3c3 - partial-whip[1]: b3n3{r3c8 r2c8} -
|| n3r1c5 - partial-whip[1]: r2n3{c6 c8} -
|| n2r6c5 - partial-whip[3]: r5n2{c6 c9} - c9n8{r5 r8} - c9n6{r8 r2} -
==> r2c8≠6
hidden-single-in-a-column ==> r4c8=6
naked-single ==> r4c7=9
z-chain[7]: c6n2{r5 r7} - r7c3{n2 n5} - r5c3{n5 n1} - r4n1{c2 c6} - r8c6{n1 n8} - c9n8{r8 r5} - r5n2{c9 .} ==> r5c6≠9
whip[5]: r8c5{n1 n9} - b5n9{r6c5 r5c4} - c4n1{r5 r8} - r8c6{n1 n8} - r2n8{c6 .} ==> r2c5≠1
whip[7]: b3n4{r2c8 r3c7} - c7n6{r3 r9} - c4n6{r9 r8} - c4n1{r8 r5} - b6n1{r5c8 r6c9} - r6n2{c9 c5} - b5n9{r6c5 .} ==> r2c8≠1
whip[7]: b5n9{r6c5 r5c4} - r8n9{c4 c6} - r8c5{n9 n1} - c4n1{r8 r2} - r2c2{n1 n5} - r4n5{c2 c6} - c6n1{r4 .} ==> r2c5≠9
OR4-forcing-whip-elim[7] based on OR4-anti-tridagon[12] for n3r3c6, n3r3c3, n3r1c5 and n2r6c5:
|| n3r3c6 - partial-whip[1]: r2n3{c6 c8} -
|| n3r3c3 - partial-whip[1]: b3n3{r3c8 r2c8} -
|| n3r1c5 - partial-whip[1]: r2n3{c6 c8} -
|| n2r6c5 - partial-whip[3]: r5n2{c6 c9} - r5n8{c9 c7} - c7n4{r5 r3} -
==> r2c8≠4
[Edit]: better notation for the OR-k-Forcing-Whips (their content is unchanged)
The end is easy:
- Code: Select all
singles ==> r3c7=4, r3c1=6, r2c1=4, r5c7=8, r9c7=6, r8c9=8, r8c1=7, r9c4=5, r7c4=7, r2c9=6, r8c4=6, r5c8=4
finned-x-wing-in-rows: n1{r4 r2}{c2 c6} ==> r3c6≠1
biv-chain[2]: r4n1{c2 c6} - c4n1{r5 r2} ==> r2c2≠1
whip[1]: r2n1{c6 .} ==> r1c5≠1
biv-chain[3]: r4n1{c2 c6} - r5c4{n1 n9} - b4n9{r5c3 r6c1} ==> r6c1≠1
biv-chain[4]: c2n2{r1 r9} - r9c5{n2 n8} - r2c5{n8 n5} - r2c2{n5 n9} ==> r1c2≠9
biv-chain[3]: c2n9{r9 r2} - c4n9{r2 r5} - b4n9{r5c3 r6c1} ==> r9c1≠9
biv-chain[4]: b7n9{r9c3 r9c2} - r2c2{n9 n5} - r2c5{n5 n8} - r9c5{n8 n2} ==> r9c3≠2
biv-chain[3]: c1n1{r1 r9} - r9c3{n1 n9} - b4n9{r5c3 r6c1} ==> r1c1≠9
singles ==> r6c1=9, r5c4=9, r2c4=1
finned-x-wing-in-rows: n1{r5 r3}{c3 c9} ==> r1c9≠1
whip[1]: b3n1{r3c9 .} ==> r3c3≠1
biv-chain[3]: r5c3{n1 n5} - r7n5{c3 c1} - r1c1{n5 n1} ==> r1c3≠1
biv-chain[3]: c1n5{r1 r7} - r7c3{n5 n2} - b1n2{r1c3 r1c2} ==> r1c2≠5
biv-chain[3]: c3n2{r7 r1} - r1n3{c3 c5} - b8n3{r7c5 r7c6} ==> r7c6≠2
singles ==> r5c6=2, r6c9=2
finned-x-wing-in-columns: n5{c2 c6}{r4 r2} ==> r2c5≠5
singles ==> r2c5=8, r9c5=2, r7c5=3, r7c6=8, r7c1=5, r1c1=1, r1c2=2, r9c1=8, r7c3=2, r1c3=3
finned-x-wing-in-columns: n5{c3 c9}{r5 r3} ==> r3c8≠5
finned-x-wing-in-columns: n5{c8 c5}{r6 r2} ==> r2c6≠5
finned-x-wing-in-columns: n5{c6 c3}{r3 r4} ==> r4c2≠5
stte