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 Post subject: Assassin 455
PostPosted: Mon Apr 01, 2024 6:47 pm 
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Grand Master
Grand Master

Joined: Wed Apr 16, 2008 1:16 am
Posts: 1044
Location: Sydney, Australia
Attachment:
a455.png
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Note: broken cage 23(4) at r3c3

Assassin 455
Nothing complicated needed but resists a long way in. A little disapointed since both SudokuSolver and JSudoku have interesting solver logs. Hope I haven't messed up. SS gives it 1.55
Spoiler alert Solvers' logs:
SudokuSolver
Puzzle Completed. Step Analysis:
7 Find Hidden Cages 4
9 Find Hidden Cages 3
13 Find Hidden Cages
69 Naked Singles
15 Naked Pairs
5 Naked Triples
1 Naked Quads
5 Hidden Singles
5 Locked Cages 2
9 Locked Candidates (Box/Line)
1 Cage Blockers
2 Cage Placement 1
5 Cage Placement
2 Killer Pairs
1 Hidden Killer Mutuals
10 Cage Combinations
16 Cage Combinations Extended
1 Cage Blockers Extended 9
1 Cage Placement Extended 1
1 Cage Placement Extended 6
2 45 Rule Single Innies/Outies
2 45 Rule Two Innies/Outies 2
2 45 Rule Two Innies/Outies
2 45 Rule Single House 4
1 45 Rule Single House 3
1 XY-Chain Simple 3
1 XY-Chain Complex 4
52 Cage Cleanup 2
1 Cage Cleanup 1
68 Cage Cleanup
2 45 Rule Extended Multiple Houses 6
1 Empty Rectangle
1 Hidden Killer Pairs
2 Locked Candidates (House/Cage)
7 Forced Cage Candidates
2 45 Rule Two Innies&Outies 2
1 45 Rule Single House Innies&Outies 4
Total solving time (seconds): 2.16
Calculated score: 1.55

JSudoku
Techniques used:
1 Last Digit
69 Naked Single
5 Hidden Single
2 Single Innies & Outies
8 Unique Pair
3 Naked Pair
2 Hidden Pair
4 Complex Hidden Single
3 Unique Triplet
12 Intersection
1 Naked Triplet
6 Odd Pairs
7 Odd Triplets
7 Double Innies & Outies
1 Hidden Quad
3 Odd Quads
2 Complex Intersection
5 Triple Innies & Outies
6 Double Outies minus Innies
3 Complex Naked Pair
2 Complex Hidden Pair
5 Quadruple Innies & Outies
3 Triple Outies minus Innies
1 Locked Cages
1 Skyscraper
2 Conflicting Partial Pair
1 Multiple Innies & Outies
triple click code:
3x3::k:2560:1537:1537:2306:4355:4355:4100:4100:4100:2560:4357:4357:2306:4355:7174:4615:4615:6152:3849:3849:5898:4107:4107:7174:4615:6152:6152:3849:3849:5898:2572:2572:7174:4615:4365:6152:5898:6926:5898:7174:7174:7174:4365:4365:4365:6926:6926:6926:7174:4367:4367:3344:4881:4881:6926:3602:2835:2835:4367:4884:3344:3344:4881:3605:3602:2835:4374:4367:4884:4375:2840:4881:3605:3605:3605:4374:4374:4884:4375:2840:2840:
solution:
+-------+-------+-------+
| 7 4 2 | 5 8 3 | 6 1 9 |
| 3 8 9 | 4 6 1 | 2 5 7 |
| 6 1 5 | 9 7 2 | 4 3 8 |
+-------+-------+-------+
| 5 3 1 | 8 2 4 | 7 9 6 |
| 9 2 8 | 6 5 7 | 3 4 1 |
| 4 6 7 | 3 1 9 | 5 8 2 |
+-------+-------+-------+
| 8 9 3 | 2 4 6 | 1 7 5 |
| 1 5 6 | 7 3 8 | 9 2 4 |
| 2 7 4 | 1 9 5 | 8 6 3 |
+-------+-------+-------+
Cheers
Ed


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 Post subject: Re: Assassin 455
PostPosted: Wed Apr 03, 2024 10:39 pm 
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Grand Master
Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada
Thanks Ed for your latest Assassin. After some routine steps I found a couple of short forcing chains, then straightforward from there with no resistance.

Here's how I solved Assassin 455:
Prelims

a) R12C1 = {19/28/37/46}, no 5
b) R1C23 = {15/24}
c) R12C4 = {18/27/36/45}, no 9
d) R2C23 = {89}
e) R3C45 = {79}
f) R4C45 = {19/28/37/46}, no 5
g) R78C2 = {59/68}
h) R89C7 = {89}
i) 11(3) cage at R7C3 = {128/137/146/236/245}, no 9
j) 19(3) cage at R7C6 = {289/379/469/478/568}, no 1
k) 11(3) cage at R8C8 = {128/137/146/236/245}, no 9
l) 14(4) cage at R8C1 = {1238/1247/1256/1346/2345}, no 9
m) 28(7) cage at R2C6 = {1234567}, no 8,9

1a. 45 rule on N14 1 outie R7C1 = 8, clean-up: no 2 in R12C1, no 6 in R78C2
1b. Naked pair {59} in R78C2, locked for C2 and N7 -> R2C23 = [89], clean-up: no 1 in R12C1, no 1 in R1C3, no 1 in R1C4
1c. Naked pair {79} in R3C45, locked for R3 and N2, clean-up: no 2 in R12C4
1d. Naked pair {89} in R89C7, locked for C7 and N9
1e. 9 in N3 only in R1C89 -> 16(3) cage at R1C7 = {169/259/349}, no 7,8
1f. R1C1 = 7 (hidden single in R1) -> R2C1 = 3, clean-up: no 6 in R1C4
1g. 45 rule on N7 1 outie R7C4 = 2 -> R78C3 = 9 = {36}, locked for C3 and N7, clean-up: no 8 in R4C5
1h. 6 in N1 only in R3C12, locked for R3 and 15(4) cage at R3C1, no 6 in R4C12
1i. 15(4) cage = {1356/2346}, no 9 -> R4C2 = 3, clean-up: no 7 in R4C45
1j. 45 rule on N2 2 innies R23C6 = {12}, locked for C6, N2 and 28(7) cage at R2C6, clean-up: no 8 in R1C4
1k. Naked quint {34567} in R4C6 + R5C456 + R6C4, locked for N5
1l. 45 rule on N8 2 remaining innies R78C5 = 7 = {16/34}
1m. 45 rule on N8 2 outies R6C56 = 10 = [19/28]
1n. 45 rule on N3 2 outies R4C79 = 13 = [49/58]/{67}, no 1,2, no 4,5 in R4C9
1o. Naked quad {1247} in 14(4) cage at R8C1, 7 locked for R9
1p. 3 in R3 only in R3C789, locked for N3, clean-up: no 4 in 16(3) cage at R1C7
1q. R1C23 = {24} (cannot be [15] which clashes with 16(3) cage), locked for R1 and N1, clean-up: no 5 in 16(3) cage, no 5 in R2C4
1r. Naked triple {169} in 16(3) cage, 1,6 locked for N3, 6 locked for R1
1s. R2C45 = {46} (hidden pair in N2), 4 locked for R2
1t. Naked triple {156} in R3C123, 1,5 locked for R3 -> R23C6 = [12]
1u. 15(4) cage = {1356} (only remaining combination, cannot be {2346} because 2,4 only in R4C1), 5 locked for C1
1v. Killer pair 4,6 in R2C5 and R78C5, locked for C5
1w. Killer pair 8,9 in R6C6 and 19(3) cage at R7C6, locked for C6 -> R1C5 = 8 (hidden single in R1)

2a. 18(4) cage at R2C7 = {2367/2457} (cannot be {3456} because R2C78 must contain two of 2,5,7), 2 locked for R2
2b. R3C7 = {34} -> no 4 in R4C7, clean-up: no 9 in R4C9
2c. 8 in R3 only in R3C89, locked for 24(4) cage at R2C9, no 8 in R4C9, clean-up: no 5 in R4C7
2d. Naked pair {67} in R4C79, locked for R4 and N6
2e. 24(4) cage at R2C9 = {3678/4578}, 7 locked for C9
2f. 45 rule on N4 4 innies R45C13 = 23 must contain 8 for N4 = {1589/4568} (cannot be {2489/2678} because R4C1 only contains 1,5), no 2,7, 5 locked for N4
2g. 6,9 only in R5C1 -> R5C1 = {69}

3a. R78C5 (step 1l) = {16/34}
3b. 19(3) cage at R7C6 = {379/478/568} (cannot be {469} which clashes with R78C5)
3c. Hidden killer pair 6,7 in R5C6 and 19(3) cage for C6, 19(3) cage only contains one of 6,7 -> R5C6 = {67}
3d. 17(3) cage at R8C4 = {179/359/458} (cannot be {368/467} which clash with R78C5), no 6
3e. 7 of {179} must be in R8C4 -> no 1 in R8C4
3f. Consider permutations for R6C56 (step 1m) = [19/28]
R6C56 = [19] => R78C5 = {34}, locked for N8 => 17(3) cage = {179}
or R6C56 = [28] => R4C45 = {19}, then caged X-Wing for 9 in R3C45 and R4C45, no other 9 in C45 => 17(3) cage = {458}
-> 17(3) cage = {179/458}, no 3
3g. 5 of {458} must be in R9C5 -> no 5 in R89C4
3h. 19(3) cage = {379/568} (cannot be {478} which clashes with 17(3) cage), no 4
3i. 45 rule on N9 3 outies R6C789 = 15 = {159/258/348} (cannot be {168/249} which clash with R6C56)
3j. Consider placement for 3 in R6
R6C4 = 3 => R12C4 = [54] => 17(3) cage = {179}
or R6C789 = {348}, 8 locked for R6 => R6C56 = [19] => R78C5 = {34}, 4 locked for N8
-> 17(3) cage = {179}
[Cracked. The rest is straightforward.]
3k. 17(3) cage = {179} -> R8C4 = 7, R3C45 = [97], R9C45 = [19], R89C7 = [98], R78C2 = [95], R4C4 = 8 -> R4C5 = 2, R6C56 = [19], clean-up: no 6 in R78C5
3l. Naked pair {34} in R78C5, locked for C5, 3 locked for N8 -> R2C5 = 6, R1C6 = 3 (hidden single in C6), R5C5 = 5, R4C6 = 4, R58C6 = [78] (hidden pair in C6)

4a. R8C1 = 1 (hidden single in N7) -> R34C1 = [65], R3C2 = 1, R34C1 = [51], R5C1 = 9 -> R5C3 =8 (cage sum)
4b. R4C8 = 9 -> R5C789 = 8 = {134}, 3,4 locked for R5 and N6 -> R5C4 = 6, R5C2 = 2, R6C1 = 4, R1C23 = [42], R9C1 = 2
4c. 3 in R9 only in R9C89 -> 11(3) cage at R8C8 = {236} (only possible combination) -> R8C8 = 2, R9C89 = {36}, locked for N9, 6 locked for R9, R8C9 = 4
4d. R2C7 = 2 (hidden single in R2), R6C7 = 5, R7C78 = 8 = {17}, 1 locked for N9 -> R7C9 = 5, R6C8 = 8
4e. R24C9 = [76] = 13 -> R3C89 = 11 = [38]

and the rest is naked singles.


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 Post subject: Re: Assassin 455
PostPosted: Wed Apr 10, 2024 6:58 pm 
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Grand Master
Grand Master

Joined: Wed Apr 16, 2008 1:16 am
Posts: 1044
Location: Sydney, Australia
Thanks Andrew. Not one of my best puzzles. I found a different way paste Andrew's chains.
end of Andrew's step 3e.:
Paste into A455 in SudokuSolver
.-------------------------------.-------------------------------.-------------------------------.
| 7 24 24 | 35 8 35 | 16 169 169 |
| 3 8 9 | 46 46 1 | 257 257 57 |
| 156 16 15 | 79 79 2 | 34 348 348 |
:-------------------------------+-------------------------------+-------------------------------:
| 15 3 1458 | 189 129 45 | 67 124589 67 |
| 69 12467 1458 | 34567 357 67 | 12345 1234589 1234589 |
| 12469 12467 1247 | 34567 12 89 | 12345 1234589 1234589 |
:-------------------------------+-------------------------------+-------------------------------:
| 8 59 36 | 2 1346 345679 | 134567 134567 13456 |
| 124 59 36 | 345789 1346 3456789 | 89 1234567 123456 |
| 124 1247 1247 | 134589 1359 345689 | 89 123456 123456 |
'-------------------------------.-------------------------------.-------------------------------'

Then
4. 17(4)r6c5 = [19]{34}/[28]{16/34}
4a. = 4 or 8
4b. = 3 or 6

5. 19(3)n8: {478} blocked by 17(4)
5a. = {379/568} (no 4)
5b. = 3 or 6

6. killer pair 3,6 in r78c5 + 19(3): 3 locked for n8

7. hidden killer pair 3,6 in r9. Only one of 3,6 can be in r9c6 -> 11(3)n9 must have at least one off
7a. 11(3) = {137/146/236}(no 5)

8. 5 in r9 only in n8: 5 locked for n8

9. 19(3)n8 = {379/568}
9a. 6 in {568} must be in r7c6
9b. -> no 6 in r89c6

10. 6 in r9 only in 11(3)n9
10a. = {146/236}(no 7)
10b. 6 locked for n9

11. 7 in n9 only in 13(3)
11a. = {157/247}(no 3)
11b. 7 locked for r7

12. hidden killer pair 1,4 in r7. Only one of 1,4 can be in r7c5 -> r7c789 must have at least one off
12a. 4 innies n9, r7c789 + r8c9 = 17 and must have 5 & 7 for n9
12b. but {357}[2] doesn't have 1 or 4
12c. = {1457} only
12d. 1 & 4 locked for n9

13. 19(4)r6c8 has no 6 nor 7, must have two of {145} for r78c9
13a. = {1459/2458}(no 3)

14. r6c4 = 3 (hsingle r6)
14a. r1c46 = [53]

15. 19(3)n8 = [685]
15a. r6c56 = [19]

16. 19(4)r6c8 = {28}{45} only: 2 locked for r6: 2 & 8 for n6
16a. 4,5 locked for n9 and c9

easy now
Cheers
Ed


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