Assassin 1 version 2

[sudokuEd]

Bit late with this one. Loosely based on Assassin 1 which needed lots of corners put into it. Rating? About average Assassin one year on - an early placement, then steady progress with that extra trick to finally break it.

Thanks for a great year 1 Ruud.

Many thanks to udosuk for adding some colour to the birthday party.

3 Cheers
Ed

3x3::k:4865:48656915:6915:6915308948652562:691569154112385818123341:6935:6935:4112385838693341:6935:6935:411215726439:6439:6439:6439:6439362746543632:49133122338146543632:491326193381:4159:46545954:4913:59543380:4431:4159:41595954:5954:59544431:4431:

[Para]

Nice puzzle, Ed. Taking out every sensible opening. Didn't keep a walk-through for reasons mentioned earlier.

Just for fun i tried assassin number 1 too. Managed to solve it without pencilmarks. Seems we've come a long way since number 1. Couldn't think of going without pencilmarks these days.

greetings

Para

[udosuk]

Greetings everyone,

This is my very first post here.

Been stalking even before the opening of this section (more than a whole year! ) and finally drag myself to actually register.

As I can see this community has prospered a lot over all this time, compared to the other forums I frequent, some of which are getting more and more quiet.

So great job Ruud! Although I don't have too much online time in the near future due to work commitments I hope I can contribute a little bit here or there.

Enough babbling. Here is my first contribution: a complete walkthrough & solution to this puzzle (including a text puzzle grid):

Code: Select all

.-----.--.--------.--.-----.
|19   |10|27      |6 |12   |
|  .--:  |  .--.  |  :--.  |
|  |8 |  |  |13|  |  |16|  |
:--:  :--'--:  :--'--:  :--:
|15|  |7    |  |27   |  |5 |
|  |  :-----:  |     |  |  |
|  |  |15   |  |     |  |  |
:--'--+-----'--'-----+--'--:
|6    |25            |14   |
:--.--+-----.--.-----+--.--:
|8 |18|14   |19|12   |13|13|
|  |  |     |  :-----:  |  |
|  |  |     |  |10   |  |  |
:--:  :--.--:  :--.--:  :--:
|16|  |11|23|  |  |6 |  |17|
|  '--:  |  '--'  |  :--'  |
|     |  |        |  |     |
'-----'--'--------'--'-----'

6/2 @ r12c7,r89c7={15|24} (NQ @ c7)
Innie-outies @ n3: r3c7-r4c89=6
=> r3c7=9, r4c89={12} (NP @ r4,n6) => r4c6<>9, r3c9=3|4
=> 16/3 @ r234c8: r23c8=14|15={68|78} (8 @ c8,n2 locked)
=> 14/2 @ r5c89 can't have 4 => 4 @ r6,c6 locked @ r6c89
=> 12/2 @ r6c67=[57|93], 10/2 @ r7c67=[28|37|46|73]
=> Innie-outies @ n9: r6c89=r7c7+4={34|46|47|48}
=> HP @ r6,n6: r5c89={59} => 6/2 @ r5c12={24} (NP @ r5,n4)

15/2 @ r34c1=[69|78|87], 15/2 @ r4c34={69|78}
r3c6+r4c67=27-9=18 must include at least 2 values from {678}
(Otherwise r3c6+r4c67 can't exceed 4+5+8=17)
r4c134 all from {6789} => Only one of r4c67 can be 6|7|8
=> r3c6=6|7|8 => r3c168={678} (NT @ r3)
=> Innie-outies @ n2: r4c5=r3c6-3=3|4|5
=> 13/3 @ r234c5: r2c5 must be from {6789}
(Otherwise r234c5 can't exceed 3+4+5=12)

7/2 @ r3c34={25} ({34} clashes r3c9) (NP @ r3)
Innie-outies @ n1: r3c3=r4c12-7 must be at least 7+3-7=3
=> r3c34=[52] => HS @ r6,n5: r6c5=2
=> r78c5=19-2=17={89} (NP @ c5,n8 )
Innies @ n8: r7c46=[14|32] => r7c67=[28|46] => r6c89={46|48}
=> 13/3 @ r678c8: r78c8=7|9 can't have 9, also can't have 7
(Otherwise r78c8={27} clashes r234c8={178|268})
=> Innies @ c8: r159c8=16 with 9 @ c8 locked
=> r159c8={259|349} ({169} clashes r234c8={178|268})
=> 7 @ c8 locked @ r23c8={78} (NP @ n3), r4c89=[12], r3c9=3

Innies @ n2: r23c5+r3c6=16 => r3c6=8, r234c5=[715], r3c2=4
=> r23c8=[87], r34c1=[69], r5c12=[42], r24c2=8-4=4=[13]
=> r4c67=27-8-9=10=[46] => r7c46=[32], r7c7=8, r6c89=[48]
=> r7c9=13-8=5 => r5c9=9, r15789c8=[25639], r12c7=[15]
=> r78c5=[98], r7c2=7 => 11/2 @ r89c3=[92]

All naked singles from here.

897543126
213976584
645218973
938754612
426831759
751629348
174392865
569487231
382165497

My fav sport
[Edited: minor typos fixed]

[sudokuEd]

Thanks for the walk-through udosuk. You cram in the info and really made me think hard!

Some very clever moves that I missed. The main one is a hidden killer quad (paragraph 2 line 4). It led a nice naked triple (para.2 ln 5) that ultimately led to the final powerful innie move in n2 (para. 4).

Another way to unlock the puzzle at the end is to notice that the 1's in c3 in r567 means 1 cannot be in r7c4.(ie: 1 in r5c3 -> 1 in n5 in r6c4 -> no 1 r7c4. 1 in r67c3 -> no 1 in r7c4 (same cage))

BTW udosuk - how do you colour up the puzzle pic? Would like to be able to do it if its not too complicated.

Seems we've come a long way since number 1.

We've taught Ruud too well .

Cheers
Ed

[udosuk]

BTW udosuk - how do you colour up the puzzle pic? Would like to be able to do it if its not too complicated.

I coloured it manually on an Excel sheet. It's quite complicated if you aren't familiar with Excel. I do have a template file to do it which caters for diagonal cages too. If you want I can email it to you.

It's a pity I'm too busy to join in all the fun activities in this forum right now...

[Andrew]

After finishing A2X I decided to have a go at A1V2, which I hadn't tried when Ed first posted it.

udosuk found a shorter solving route with a better version of step 4 and Ed's message gives a neat alternative finish.

I'll rate A1V2 as a solid 1.25. The two improvements mentioned above would make it a slightly easier 1.25.

Here is my walkthrough for A1V2.

Prelims

a) R12C3 = {19/28/37/46}, no 5
b) R12C7 = {15/24}
c) R3C34 = {16/25/34}, no 7,8,9
d) R34C1 = {69/78}
e) R34C9 = {14/23}
f) R4C34 = {69/78}
g) R5C12 = {15/24}
h) R5C89 = {59/68}
i) R67C1 = {17/26/35}, no 4,8,9
j) R6C67 = {39/48/57}, no 1,2,6
k) R67C9 = {49/58/67}, no 1,2,3
l) R7C67 = {19/28/37/46}, no 5
m) R89C3 = {29/38/47/56}, no 1
n) R89C7 = {15/24}
o) 19(3) cage in N1 = {289/379/469/478/568}, no 1
p) R234C2 = 1{25/34}, 1 locked for C2, clean-up: no 5 in R5C1
q) R678C5 = {289/379/469/478/568}, no 1
r) 27(4) cage at R3C6 = {3789/4689/5679}
s) 14(4) cage at R6C3 = {1238/1247/1256/1346/2345}, no 9

1. Naked quad {1245} in R1289C7, locked for C7, clean-up: no 7,8 in R6C6, no 6,8,9 in R7C7

2. 45 rule on C2 3 innies R159C2 = 19 = {289/469/478/568} (cannot be {379} because no 3,7,9 in R5C2), no 3
2a. R5C2 = {245} -> no 2,4,5 in R19C2

3. R678C2 = {279/369/378/567} (cannot be {459} which clashes with R234C2, cannot be {468} which clashes with R159C2), no 4

4. 45 rule on N3 2 innies R3C79 = 1 outie R4C8 + 11, max R3C79 = 13 -> max R4C8 = 2
4a. R3C79 = 12,13 = [84/93/94], clean-up: no 3,4 in R4C9
4b. R3C34 = {16/25} (cannot be {34} which clashes with R3C9)
[udosuk gave the better version 1 innie R3C7 = 2 outies R4C89 + 6 -> R3C7 = 9, R4C89 = {12}, locked for R4 and N6.]

5. Naked pair {12} in R4C89, locked for R4 and N6

6. 1 in 8(3) cage locked in R23C2, locked for C2, clean-up: no 9 in R12C3, no 6 in R3C4
6a. R234C2 = 1{25/34}
6b. 5 of {125} must be in R4C2 -> no 5 in R23C2

7. 4 in N6 locked in R6C89, locked for R6, clean-up: no 8 in R6C7

8. R234C8 = {69}1/{78}1/{59}2/{68}2, no 1,2,3,4 in R23C8
8a. Killer pair 8,9 in R3C7 and R23C8, locked for N3

9. 12(3) cage in N3 = {156/237/246} (cannot be {147} which clashes with R12C7, cannot be {345} which clashes with R3C9)

10. 27(4) cage at R3C6 = {3789/4689/5679}
10a. R4C67 cannot both be {6789} which would clash with R4C134 -> no 3,4,5 in R3C6
10b. 4,5 of {4689/5679} must be in R4C6 -> no 6 in R4C6
10c. Killer quad 6,7,8,9 in R4C134 and R4C67, locked for R4

11. Hidden killer quad 1,2,3,4 in R3C2, R3C34, R3C5 and R3C67 for R3 -> R3C5 = {1234}

12. R234C5 = {139/148/157/238/247/256/346}
12a. 6,7,8,9 only in R2C5 -> R2C5 = {6789}

13. 45 rule on N7 2 innies R7C13 = 1 outie R6C2, min R7C13 = 3 -> min R6C2 = 3

14. 45 rule on N9 2 innies R7C79 = 1 outie R6C8 + 9, max R7C79 = 17 -> max R6C8 = 8

15. 45 rule on N2 2 innies R3C46 = 1 outie R4C5 + 5, max R4C5 = 5 -> max R3C46 = 10, no 5 in R3C4, clean-up: no 2 in R3C3
15a. R89C3 = {29/38/47} (cannot be {56} which clashes with R3C3), no 5,6

16. 19(3) cage in N1 = {289/379/469/478} (cannot be {568} which clashes with R3C3), no 5

17. R3C3 = 5 (hidden single in N1), R3C4 = 2

18. 45 rule on N1 2 outies R4C12 = 12, no 6 in R4C1, clean-up: no 9 in R3C1
18a. 45 rule on R4, R4C12 = 12, R4C34 = 15, R4C89 = 3 -> R4C567 = 15 = {348/357/456}, no 9
18b. 9 in 27(4) cage locked in R3C67, locked for R3

19. R234C8 (step 8) = {78}1/{68}2/[961] (cannot be {59}2 because 5,9 only in R2C8), no 5

20. 45 rule on R12 3 innies R2C258 = 16, min R2C58 = 13 -> max R2C2 = 3

21. 45 rule on N2 3 remaining innies R2C5 + R3C56 = 16, min R2C5 + R3C6 = 13
-> max R3C5 = 3

22. 45 rule on C5 3 innies R159C5 = 13 = {148/157/238/247/256/346} (cannot be {139} which clashes with R3C5), no 9

23. 4 in N6 locked in R6C89
23a. 45 rule on N9 3 outies R7C6 + R6C89 = 14
23b. No 5 in R7C6 -> R6C89 cannot be 9, no 5 in R6C89, clean-up: no 8 in R7C9

24. 5 in N6 locked in R5C89 -> R5C89 = {59}, locked for R5 and N6, clean-up: no 1 in R5C1, no 3 in R6C6, no 4 in R7C9
24a. Naked pair {24} in R5C12 , locked for R5 and N4, clean-up: no 6 in R7C1
24b. No 9 in R6C9 -> max R6C89 = 12, no 1 in R7C6 (step 23a), clean-up: no 9 in R7C7

25. R234C2 (step 6a) = 1{25/34}
25a. 4 of {134} must be in R3C2 -> no 3 in R3C2

26. Killer pair 2,4 in R234C2 and R5C2, locked for C2

27. R3C7 = 9 (hidden single in C7)

28. R234C8 (step 19) = {78}1/{68}2, 8 locked for C8

29. R6C5 = 2 (hidden single in R6), R78C5 = 17 = {89}, locked for C5 and N8

30. R234C5 (step 12) = {157/346}
30a. 4 of {346} must be in R4C5 -> no 3 in R4C5

31. 4,5,9 in N2 locked in 27(5) cage = {14589/34569}, no 7

32. 45 rule on N8, 4 innies R7C456 + R8C5 = 22, R78C5 = 17 -> R7C46 = 5 = [14/32], clean-up: no 3,7 in R7C7

33. 3,7 in C7 locked in R456C7, locked for N6, clean-up: no 6 in R7C9

34. 14(4) cage at R6C3 = {1238/1256/1346} (cannot be cannot be {1247/2345} because 2,4 only in R7C3), no 7
34a. 2,4 only in R7C3 -> R7C3 = {24}

35. Naked pair {24} in R7C36, locked for R7, clean-up: no 6 in R6C1

36. Killer triple 2,3,4 in R12C3, R7C3 and R89C3, locked for C3

37. R678C8 = [436/463/472/634/652], no 1,9, no 5,7 in R8C8

38. Killer pair 6,7 in R23C8 and R678C8, locked for C8

39. 45 rule on C8 3 innies R159C8 = 16 = {259/349}, no 1

40. R4C8 = 1 (hidden single in C8), R4C9 = 2, R3C9 = 3, R3C5 = 1, R3C2 = 4, R24C2 = [13] (step 6a), R5C12 = [42], R24C5 = [75] (step 30), R6C67 = [93], clean-up: no 3 in R1C3, no 6 in R12C3, no 5 in R1C7, no 6 in R4C3, no 5 in R7C1

41. R4C6 = 4 (hidden single in R4), R7C67 = [28], R7C3 = 4, R7C4 = 3 (step 32), R78C5 = [98], clean-up: no 5 in R6C1, no 7 in R89C3, no 3 in R9C3

42. R6C34 = {16} (step 34), locked for R6 -> R67C1 = [71], R6C8 = 4, R6C9 = 8, R7C9 = 5, R5C89 = [59], R1C8 = 2, R9C8 = 9 (step 39), R6C2 = 5, clean-up: no 8 in R2C3, no 4 in R12C7 = [15], no 8 in R34C1 = [69], R4C3 = 8, R4C4 = 7, R4C7 = 6, R5C7 = 7, R3C6 = 8 (cage sum), R3C8 = 7, R78C8 = [63], R2C8 = 8, R7C2 = 7, R8C2 = 6 (cage sum)

and the rest is naked and hidden singles