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HATMAN
 Post subject: NCKillers 2, 3, 4
PostPosted: Tue Jun 25, 2013 11:13 am 
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Grand Master
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Joined: Wed Apr 30, 2008 9:45 pm
Posts: 694
Location: Saudi Arabia
NCKiller 2

All three are reasonably Standard Killers except that cages cannot contain consecutive numbers in any positions.

E.g. 13(3) = 139/148/157/247

Note this one is an X.

If you solve them please comment on the difficulty, as I will be doing a few and want to check my difficulty levels.

Image
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JS Code:
3x3:d:k:4609:4609:9:14:15:16:17:4866:4866:4609:4609:18:19:20:3340:3340:4866:4866:5640:5640:21:22:23:24:25:26:3339:5640:5640:27:28:4621:4621:29:30:3339:31:32:33:34:4621:4621:35:36:37:38:39:5383:5383:40:5125:5125:5126:5126:41:42:5383:5383:43:5125:5125:5126:5126:5123:5123:44:45:46:4106:4106:5380:5380:5123:5123:47:48:49:4106:4106:5380:5380:
Solution:

182395746
635274981
497168235
723419658
849653172
561782493
254936817
918527364
376841529


NCKiller 3

This one has seven extra groups: Old Lace, 4 rims and a couple of odd ones. Note the white areas are not extra groups.

Image
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JS Code:
3x3::k:4609:4609:10:5127:5127:5127:5127:4868:4868:4609:4609:11:12:13:14:15:4868:4868:16:17:18:19:3592:20:21:22:23:24:25:26:3592:27:3849:28:29:30:31:32:3592:33:3849:4870:4870:34:35:36:37:38:3849:39:4870:4870:6149:6149:40:41:42:43:44:45:46:6149:6149:5635:5635:47:48:49:50:51:4866:4866:5635:5635:52:53:54:55:56:4866:4866:

Solution:

597286431
132547869
468391572
679412385
381759624
254863197
816974253
925138746
743625918


NCKiller 4

No extra constraints.

Image
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JS Code:
3x3::k:4609:4609:5123:5123:4:4:18:19:20:4866:4609:4609:5123:5123:4:4:5900:5900:4866:4866:21:22:23:4621:4621:5900:24:5126:4866:25:26:27:4621:4621:5900:28:5126:5126:29:30:4366:4366:31:4619:4619:32:5126:33:34:4366:4366:6159:5130:4619:3344:35:36:6159:6159:6159:37:5130:4619:3344:38:4872:4872:5641:5641:39:40:5130:3344:3345:3345:4872:4872:5641:5641:41:5130:

Solution:

532419687
491687352
687523194
213946875
849751263
765238941
926375418
174892536
358164729
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wellbeback
 Post subject: Re: NCKillers 2, 3, 4
PostPosted: Tue Jun 25, 2013 8:10 pm 
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Joined: Tue Jun 16, 2009 9:31 pm
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Location: California, out of London
Here is a walkthrough and rating for NC Killer (2) (The first one in this set). Thanks HATMAN!
(Note: Edited to eliminate an either/or path).
Hidden Text:
1. 16/4@r8c6 = {1357}

2. 19/4@r1c8 = {16(39|48)} - One of 4 or 9
21/4@r8c8 = {49(17|26)} - Both 4 and 9
-> 20/4@r6c8 = {1379} or {2468} - One of 4 or 9
-> no other 4s or 9s in c89
-> 13/2@r3c9 = {58}
Also 20/4@r6c8 cannot be {1469}

3. Neither 20/4 nor 21/4 can contain a 5.
-> 5 in n9 in r89c7.

4. 20/4@r6c8 from {1379} or {2468}
-> +r7c89 is even
-> r7c7 is even
-> 20/4@r6c6 = {46(19|28)} - Contains a 4.
Since 21/4@r6c3 = {49(17|26)} - Contains a 4.
-> 20/4@r6c8 cannot contain a 4.
-> 20/4@r6c8 = {1379}
-> Since 21/4@r8c8 contains a 9 -> 19/4@r1c8 cannot contain a 9 - must be {1468}
-> 21/4@r8c8 cannot contain a 1 - must be {2469}

5. HS 8 in n9 -> r7c7 = 8
-> 20/4@r6c6 = {2468}
Also 13/2@r3c9 = [58]
Also 13/2@r2c6 = [49]
-> r6c7 = 4
-> r67c6 = {26}

6. Also 9 in r6c89
-> r7c34 = {49}
-> r6c34 = [17] (Since 18/4@r4c5 must contain a 1)
-> r7c89 = {17} and r6c89 = {39}
-> r89c6 = {17} and r89c7 = {35}

7. 18/4 cannot contain a 4
-> 4 in n5 in r45c4
-> r7c34 = [49]
-> 20/4@r8c1 = {1379}

8. Also 4 in r1c89
-> 4 in r3c12
-> 22/4@r3c1 = {2479}

9. 8 in n7 in r89c3
-> 8 in n1 in r1c2 or r2c1
-> 18/4@r1c1 = {1368}

10. 9 in n5 in r45c56
-> 18/4@r4c5 = {1359}

11. All cages contents identified. Rest is "Vanilla Killa" elimination solving.

Rating - Hard 1.0.


Last edited by wellbeback on Tue Jul 23, 2013 5:24 pm, edited 1 time in total.

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HATMAN
 Post subject: Re: NCKillers 2, 3, 4
PostPosted: Thu Jun 27, 2013 3:59 pm 
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Posts: 694
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Wellbeback

In solving the cages you appear not to have used the diagonals - no doubt a challenge that you appreciated.

Your #4 was a nice move I avoided it by using diagonals: d/ only has 5 in the 18(4) cage hence {1359} from C6 the 20(4) at r6c6 has to be 2468 else not enough evens in the column - slightly easier I think.

corrected - thanks Andrew


Last edited by HATMAN on Tue Jul 23, 2013 7:04 pm, edited 1 time in total.

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wellbeback
 Post subject: Re: NCKillers 2, 3, 4
PostPosted: Sat Jun 29, 2013 4:55 pm 
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Joined: Tue Jun 16, 2009 9:31 pm
Posts: 282
Location: California, out of London
You are quite right - your diagonal method was easier than mine. I often have a blind spot when it comes to diagonals.

By the way - my ratings for the other two puzzles in this set are about the same as for the first one. The second one appeared to be harder despite not having any more technically difficult moves. Probably just because of the irregularly shaped groups.

Also - the two 11x11 puzzles on the similar theme you posted on the other forum. They took me a while. Again, not because they required technically difficult moves but probably because it just took longer to spot the moves. A question about them is: The solutions were absolutely regular. Each row/column was rotated from the previous row/column. Is this a forced consequence of the rules? (NC, Fers-NC, Anti-King).
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HATMAN
 Post subject: Re: NCKillers 2, 3, 4
PostPosted: Mon Jul 01, 2013 12:43 pm 
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I believe it is - the solution set is very constrained - though I do not have proof.
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Andrew
 Post subject: Re: NCKillers 2, 3, 4
PostPosted: Mon Jul 22, 2013 1:33 am 
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I set up worksheets for these puzzles when they first appeared, but have only just started trying them; I've been busy on other things including watching three weeks of the Tour de France and doing HATMAN's interesting CNC Killers.

NC Killer 2 is an enjoyable puzzle. :)

Here is my walkthrough for NC Killer 2:
Cages cannot contain consecutive numbers, even if they aren’t adjacent. There is no other condition about non-consecutive numbers.

1a. R2C67 = {49/58}
1b. R34C9 = {49/58}

2. 16(4) cage at R8C6 = {1357} (only valid combination)

3. 18(4) cage at R1C1 = {1359/1368}, no 2,4,7, 1,3 locked for N1

4. 19(4) cage at R1C8 = {1369/1468}, no 2,5,7, 1,6 locked for N3

5. 18(4) cage at R4C5 = {1359/1368}, no 2,4,7, 1,3 locked for N5

6. 22(4) cage at R3C1 = {1579/2479}, no 3,6,8

7. 21(4) cage at R6C3 = {1479/2469}, no 3,5,8

8. 20(4) cage at R6C6 = {1379/1469/2468}, no 5

9. 20(4) cage at R6C8 = {1379/1469/2468}, no 5

10. 20(4) cage at R8C1 = {1379/1469/2468}, no 5

11. 21(4) cage at R8C8 = {1479/2469}, no 3,5,8, 4,9 locked for N9

12. 5 in N9 only in R89C7, locked for C7 and 16(4) cage at R8C6, no 5 in R89C6, clean-up: no 8 in R2C6
12a. 8 in N9 only in R7C789, locked for R7
12b. 5 in N3 only in R3C89, locked for R3
12c. 1 in R3 only in R3C456, locked for N2

13. 19(4) cage at R1C8 contains one of 4,9, 20(4) cage at R6C8 contains at least one of 4,9, 21(4) cage at R8C8 contains both of 4,9 -> no other 4,9 in C89
13a. 20(4) cage at R6C8 can only contain one of 4,9 = {1379/2468}
13b. Naked pair {58} in R34C9, locked for C9

14. 5 on D/ only in R4C6 + R5C5, locked for N5
14a. 18(4) cage at R4C5 = {1359} (only remaining combination), locked for N5

15. 5 in C8 only in R345C8, 5 in C9 only in R34C8, 18(4) cage at R4C5 = {1359} form some sort of Swordfish(?) for R345, no other 5 in R345
15a. 22(4) cage at R3C1 = {2479} (only remaining combination), no 1

16. 21(4) cage at R6C3 contain both of 4,9, 20(4) cage at R6C6 contains at least one of 4,9 and 20(4) cage at R6C8 contains one of 4,9 -> no other 4,9 in R67
16a. 20(4) cage at R6C6 can only contain one of 4,9 = {1379/2468}
16b. 20(4) cage at R6C6 = {2468} (only remaining combination, cannot be {1379} which clashes with R45C6 + R89C6, ALS block)
[Alternatively, as HATMAN expressed it, {1379} would leave not enough evens in C6.]
16c. 20(4) cage at R6C6 contains 4 -> 20(4) cage at R6C8 (step 13a) must contain 9 = {1379}, 9 locked for R6 and N6

17. 9 in C7 only in R123C7, locked for N3
17a. 19(4) cage at R1C8 = {1468} (only remaining combination), locked for N3 -> R2C7 = 9, R2C6 = 4, R34C9 = [58]

18. R7C7 = 8 (hidden single in N9), placed for D\, R67C6 = {26}, locked for C6 and 20(4) cage at R6C6 -> R6C7 = 4
18a. 8 in C6 only in R13C6, locked for N2
18b. 6 in C7 only in R45C7, locked for N6

19. 21(4) cage at R8C8 = {2469} (hidden quad in N9)

20. R1C1 + R2C2 + R5C5 = {135} (hidden triple on D\)

21. 7 on D\ only in R3C3 + R4C4
21a. Grouped X-Wing for 7 in 22(4) cage at R3C1 and R3C3 + R4C4, no other 7 in R34
21b. Naked pair {23} in R3C78, locked for R3 and N3 -> R1C7 = 7
21c. 7 in N9 only in R7C89, locked for R7 and 20(4) cage at R6C8, no 7 in R6C89
21d. 7 in N6 only in R5C89, locked for R5
21e. 16(4) cage at R8C6 = {1357}, 7 locked for N8

22. 22(4) cage at R3C1 = {2479}, 2 locked for R4 and N4

23. 21(4) cage at R6C3 = {1479} (only remaining cage, cannot be {2469} which clashes with R6C6) -> R6C3 = 1, R6C4 = 7, placed for D/, R7C34 = {49}
23a. 4 in N5 only in R45C4, locked for C4 -> R7C4 = 9, R7C3 = 4, placed for D/

24. Naked pair {16} in R12C9, locked for C9 and N3 -> R2C8 = 8, placed for D/, R1C8 = 4
24a. 4 in R3 only in R3C12, locked for 22(4) cage at R3C1, no 4 in R4C12
24b. R4C4 = 4 (hidden single in R4), placed for D\
24c. R8C9 = 4 (hidden single in N9)
24d. R9C5 = 4 (hidden single in N8)

25. 20(4) cage at R8C1 = {1379} (only remaining combination), locked for N7
25a. 3 in C3 only in R45C3, locked for N4
25b. 3 in R6 only in R6C89, locked for 20(4) cage at R6C8 and N6 -> R7C89 = [17], R5C9 = 2, R9C9 = 9, placed for D\, R45C8 = [57], R6C89 = [93]
25c. Naked pair {35} in R89C7, locked for C7 and 16(4) cage at R8C6, no 3 in R89C6 -> R3C78 = [23]

26. R1C9 = 6 (hidden single on D/), R2C9 = 1
26a. R5C5 = 5 (hidden single on D/ and in R5 and N5), placed for D\ -> R2C2 = 3, R1C1 = 1, R9C1 = 3, placed for D/, R89C7 = [35]

27. R3C3 = 7 (hidden single on D\), R3C12 = {49}, locked for R3, N3 and 22(4) cage at R3C1, no 9 in R4C12

28. 18(4) cage at R1C1 = {1368} (only remaining combination) -> R1C2 = 8, R2C1 = 6

29. Naked pair {17} in R89C6, locked for C6 and N8 -> R3C6 = 8, R4C6 = 9, placed for D/, R8C2 = 1

and the rest is naked singles, without using the diagonals.

Rating Comment:
Rating Comment. I'll rate my walkthrough for NC Killer 2 at least Hard 1.0. I used lots of double killer pairs, X-Wings and a sort of Swordfish(?).
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Andrew
 Post subject: Re: NCKillers 2, 3, 4
PostPosted: Tue Jul 23, 2013 5:16 am 
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NC Killer 3 was another enjoyable puzzle. I found it easier than NC2 :) , although I did use one technically harder step; there maybe a longer way to avoid it, in which case it's a nice shortcut.

Here is my walkthrough for NC Killer 3:
Cages cannot contain consecutive numbers, even if they aren’t adjacent. There is no other condition about non-consecutive numbers.

In addition to the cages and the normal killer nonets, there are 7 irregular nonets which I’ve labelled A to G in my diagram; group D is an Old Lace.

Image

Prelims

a) 14(3) cage at R3C5 = {149/158/248/257}, no 3
b) 15(3) cage at R4C6 = {159/168/249/258/357}
c) 18(4) cage at R1C1 = {1359/1368}, no 2,4,7
d) 20(4) cage at R1C4 = {1379/1469/2468}, no 5
e) 19(4) cage at R1C8 = {1369/1468}, no 2,5,7
f) 19(4) cage at R5C6 = {1369/1468}, no 2,5,7
g) 24(4) cage at R6C8 = {3579}
h) 22(4) cage at R8C1 = {1579/2479}, no 3,6,8
i) 19(4) cage at R8C8 = {1369/1468}, no 2,5,7

Steps resulting from Prelims
1a. 18(4) cage at R1C1 = {1359/1368}, 1,3 locked for N1
1b. 19(4) cage at R1C8 = {1369/1468}, 1,6 locked for N3
1c. 22(4) cage at R8C1 = {1579/2479}, 7,9 locked for N7
1d. 19(4) cage at R8C8 = {1369/1468}, 1,6 locked for N9
1e. 1 in R3 only in R3C456, locked for N2
1f. 1,6 in C7 only in R456C7, locked for N6

2. 20(4) cage at R1C4 = {2468} (only remaining combination), locked for R1, 6 also locked for N2
2a. R1C3 = 7 (hidden single in R1), placed for group A
2b. 7 in C1 only in R689C1, locked for group G

3. 5 in R1 only in R1C12, locked for N1 and group A
3a. 18(4) cage at R1C1 = {1359}, locked for N1
3b. 9 in C3 only in R456C3, locked for N4
3c. 9 in group A only in R1C12 + R2C1, locked for 18(4) cage, no 9 in R2C2

4. R1C89 = {139} -> 19(4) cage at R1C8 = {1369}, locked for N3, 6 also locked for R2
4a. 3,9 in R3 only in R3C456, locked for N2

5. Caged X-Wing for 3,9 in 19(4) cage at R1C8 and 24(4) cage at R6C8, no other 3,9 in C89
5a. Naked quad {1468} in 19(4) cage at R8C8, locked for N9
5b. 2 in N9 only in R789C7, locked for C7
5c. 2 in R1 only in R1C456, locked for N2
5d. R2C3 = 2 (hidden single in R2)
5e. Naked triple {468} in R3C123, locked for R3
5f. Naked triple {257} in R3C789, locked for R3 and N3
5g. Naked pair {48} in R12C7, locked for C7

6. R1C89 + R2C9 = {139} (hidden triple in group B), locked for N3 -> R2C8 = 6
6a. R1C6 = 6 (hidden single in group B)
6b. 19(4) cage at R5C6 = {1369/1468}, 6 locked for C7
6c. 6 in N9 only in R89C9, locked for group F
6d. 6 in group A only in R345C1, locked for C1

7. 14(3) cage at R3C5 = {149/158} (cannot be {248/257} because R3C5 only contains 1,9), no 2,6,7, 1 locked for group D
7a. 15(3) cage at R4C6 = {249/258/357}, no 6
7b. Combined 14(3) cage + 15(3) cage = {149}{258}/{149}{357}/{158}{249}, 4,5,9 locked for group D
7c. Remaining cells in group D R5C7 + R6C6 + R7C5 = 16 = {268/367} -> R7C5 = {27}, R5C7 = 6
7d. 6 in C4 only in R789C4, locked for N8

8. R37C5 “see” all cells of N5 except for R5C46 (Old Lace property)
8a. R7C5 = {27} -> R5C4 = {27} (because no 2,7 in R5C6)
8b. R3C5 = {19} -> R5C6 = {19}
8c. 19(4) cage at R5C6 = {1369} (only remaining combination) -> R6C6 = 3, R7C5 = 7 (step 7c), R5C4 = 7
8d. R2C6 = 7 (hidden single in N2), placed for group B, R3C4 = 3 (hidden single in N2), R4C7 = 3 (hidden single in N6)
8e. R6C7 = 1 (hidden single in N6), R5C6 = 9, R3C6 = 1
8f. R3C5 = 9, R4C4 + R5C3 = 5 = {14}, locked for group D
8g. Naked pair {14} in R4C4 + R5C3, CPE no 1,4 in R4C123
8h. Naked triple {258} in 15(3) cage at R4C6, locked for N5
8i. R4C2 = 7 (hidden single in N4)
8j. 4 in C6 only in R789C6, locked for N8

9. R6C89 = {79} (hidden pair in N6), locked for R6 and 24(4) cage at R6C8, no 9 in R7C89
9a. Naked pair {35} in R7C89, locked for R7 and N9
9b. R6C9 + R9C7 = {79} (hidden pair in group F)

10. R3C7 = 5 (hidden single in C7), placed for group C, R3C9 = 2, placed for group B, R3C8 = 7, R5C8 = 2 (hidden single in N6), R6C8 = 9, R6C9 = 7, placed for group F, R9C7 = 9, R78C7 = [27]
10a. R9C1 = 7 (hidden single in R9)
10b. 2 in group F only in R9C56, locked for R9 and N8

11. 9 in group G only in R8C14, locked for R8
11a. R8C1 = 9 (hidden single in N7
11b. Naked pair {13} in R2C12, locked for R2 and N1 -> R1C12 = [59], R2C9 = 9

12. R2C4 = 5 (hidden single in R2)
12a. 5 in group B only in R4C89, locked for R4 and N4
12b. R5C5 = 5 (hidden single in N5)

13. R9C3 = 3 (hidden single in group G)
13a. R8C5 = 3 (hidden single in N8), locked for group E
13b. R5C1 = 3 (hidden single in R5), R2C12 = [13]

14. R8C2 = 2 (hidden single in group E), R9C2 = 4 (cage sum), placed for group G, R7C9 = 8, placed for group G, R6C1 = 2, R4C9 = 6, R3C9 = 4, placed for group A

15. R7C9 = 3 (hidden single in group F)

and the rest is naked singles, without using the special groups.

Rating Comment:
I'll rate my walkthrough for NC Killer 3 at Easy 1.5 because I used an Old Lace "sees all except" step.
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Andrew
 Post subject: Re: NCKillers 2, 3, 4
PostPosted: Tue Jul 23, 2013 11:26 pm 
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Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada
And then I found that NC Killer 4 was the easiest of these three puzzles.

Here is my walkthrough for NC Killer 4:
Cages cannot contain consecutive numbers, even if they aren’t adjacent. There is no other condition about non-consecutive numbers.

Prelims

a) R9C23 = {49/58}
b) 13(3) cage at R7C1 = {139/148/157/247}, no 6
c) 18(4) cage at R1C1 = {1359/1368}, no 2,4,7
d) 20(4) cage at R1C3 = {1379/1469/2468}, no 5
e) 20(4) cage at R1C5 = {1379/1469/2468}, no 5
f) 19(4) cage at R2C1 = {1369/1378/1468}, no 2,5
g) 23(4) cage at R2C8 = {2579}
h) 18(4) cage at R3C6 = {1359/1368}, no 2,4,7
i) 20(4) cage at R4C1 = {1379/1469/2468}, no 5
j) 17(4) cage at R5C5 = {1358/1367}, no 2,4,9
k) 18(4) cage at R5C8 = {1359/1368}, no 2,4,7
l) 24(4) cage at R6C7 = {3579}
m) 20(4) cage at R6C8 = {1379/1469/2468}, no 5
n) 19(4) cage at R8C3 = {1369/1378/1468}, no 2,5
o) 22(4) cage at R8C5 = {1579/2479}, no 3,6,8

1. 18(4) cage at R1C1 = {1359/1368}, 1,3 locked for N1
1a. 19(4) cage at R2C1 = {1468} (only remaining combination because 1,3 only in R4C2) -> R4C2 = 1, R2C1 + R3C12 = {468}, locked for N1
1b. Naked quad {1359} in 18(4) cage, locked for N1
1c. Naked pair {27} in R13C3, locked for C3
1d. 18(4) cage at R3C6 = {1359/1368}, 1 locked for R3

2. 17(4) cage at R5C5 = {1358/1367}, 1,3 locked for N5

3. 2 in N8 only in 22(4) cage at R8C5 = {2479}, no 2 in R9C7

4. 6,8 in N8 only in 19(4) cage at R8C3 = {1468} -> R8C3 = {14}
4a. 19(4) cage at R8C3 = {1468}, CPE no 4 in R8C56
4b. Naked quint {23579} in R7C456 + R8C56, locked for N8 -> R9C6 = 4, R8C3 = 4, clean-up: no 9 in R9C23
4c. Naked pair {58} in R9C23, locked for R9 and N7
4d. Naked pair {16} in R9C45, locked for R9 and N8 -> R8C4 = 8

5. 3,5 in N8 in R7C456, locked for R7 and 24(4) cage at R6C7, no 3,5 in R6C7
5a. Naked pair {79} in R69C7, locked for C7

6. 13(3) cage at R7C1 = {139} (only remaining combination), locked for C1 and N7 -> R1C1 = 5, R7C3 = 6
6a. Naked pair {39} in R12C2, locked for C2 and N1 -> R3C2 = 1
6b. Naked pair {27} in R78C2, locked for C2
6c. R9C2 = 5 (hidden single in C2), R9C3 = 8

7. 20(4) cage at R4C1 = {2468} (only remaining combination), locked for N4 -> R6C1 = 7, R69C7 = [97]
7a. Naked pair {29} in R8C56, locked for R8 -> R78C2 = [27]

8. 20(4) cage at R1C3 = {2468} (only remaining combination, cannot be {1379} which clashes with R2C2, cannot be {1469} because R1C3 only contains 2,7) -> R1C3 = 2, R2C5 = 8, R12C4 = {46}, locked for C4 and N2

9. 20(4) cage at R1C5 = {1379} (only remaining combination, cannot be {1469} because 4,6 only in R2C7) -> R2C7 = 3, R12C2 = [39], R2C6 = 7, R1C56 = {19}, locked for R1 and N2

10. Naked pair {35} in R37C6, locked for C6
10a. 18(4) cage at R3C6 = {1359/1368} -> R3C6 = 3, R3C7 = 1, R7C6 = 5

11. Naked pair {25} in R2C89, locked for N3 and 23(4) cage at R2C8 -> R34C8 = [97]

12. 17(4) cage at R5C5 = {1358/1367}, 3 locked for C5 -> R7C45 = [37]
12a. 17(4) cage = {1358} (only remaining combination) -> R56C5 = {35}, locked for C5 and N5, R56C6 = {18}, locked for C6 -> R1C56 = [19], R3C45 = [52], R456C4 = [972], R4C6 = 6, R4C7 = 8 (cage sum), R4C5 = 4, R4C1 = 2, R7C7 = 4, R1C7 = 6, R12C4 = [46], R1C89 = [87]

13. 20(4) cage at R6C8 = {1469} (only remaining combination) -> R6C8 = 4, R8C9 = 6, R9C9 = 9, R7C8 = 1

14. 18(4) cage at R5C8 = {1368} (only remaining combination) -> R5C8 = 6, R56C9 = {13}, locked for C9 -> R4C9 = 5

and the rest is naked singles.

Rating Comment:
I'll rate my walkthrough for NC Killer 4 at 1.0; I only used CPEs and simple combination blocking.
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