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 Post subject: Human Solvable 25
PostPosted: Fri Aug 07, 2020 5:46 pm 
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Grand Master
Grand Master

Joined: Wed Apr 30, 2008 9:45 pm
Posts: 693
Location: Saudi Arabia
HS 25

I was making HS25 when HS26 came up by accident, but I was never able to complete it. Hence this is HS25.
JS uses 35 fishes and SS gives it 2.75.


Image

JS Code:
3x3::k:4369:3849:3849:3849:4111:6918:6918:6918:3858:7434:4369:3849:5141:4111:4111:6918:3858:2841:7434:7434:4369:5141:5141:4111:3858:2841:2841:7434:5910:5910:26:5141:27:28:29:2841:3854:3854:5910:5910:30:31:32:3341:3341:2824:3854:3854:33:7192:34:3341:3341:6924:2824:2824:3860:3600:7192:7192:4371:6924:6924:2824:3860:6919:3600:3600:7192:4363:4371:6924:3860:6919:6919:6919:3600:4363:4363:4363:4371:


Solution:
621953784
873264951
954871623
746132895
198547362
532698147
215786439
369415278
487329516


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 Post subject: Re: Human Solvable 25
PostPosted: Mon Aug 10, 2020 3:54 am 
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Grand Master
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Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1893
Location: Lethbridge, Alberta, Canada
Thanks HATMAN. Lots of interesting interactions. Don't know whether I found a Human Solvable step, it didn't feel like I did, but I only used one forcing chain.

Here's my walkthrough for Human Solvable 25:
Prelims

a) 27(4) cage at R1C6 = {3789/4689/5679}, no 1,2
b) 29(4) cage at R2C1 = {5789}
c) 11(4) cage at R2C9 = {1235}
d) 13(4) cage at R5C8 = {1237/1246/1345}, no 8,9
e) 11(4) cage at R6C1 = {1235}
f) 28(4) cage at R6C5 = {4789/5689}, no 1,2,3
g) 27(4) cage at R6C9 = {3789/4689/5679}, no 1,2
h) 14(4) cage at R7C4 = {1238/1247/1256/1346/2345}, no 9
i) 27(4) cage at R8C3 = {3789/4689/5679}, no 1,2

1a. 11(4) cage at R2C9 = {1235}, CPE no 1,2,3,5 in R1C9
1b. 29(4) cage at R2C1 = {5789}, CPE no 5,7,8,9 in R1C1
1c. 11(4) cage at R6C1 = {1235}, CPE no 1,2,3,5 in R9C1
1d. 27(4) cage at R1C6 = {3789/4689/5679}, CPE no 9 in R1C9
1e. 27(4) cage at R6C9 = {3789/4689/5679}, CPE no 9 in R9C9
1f. 27(4) cage at R8C3 = {3789/4689/5679}, CPE no 9 in R9C1
1g. 28(4) cage at R6C5 = {4789/5689}, CPE no 8 in R89C5
1h. 13(4) cage at R5C8 = {1237/1246/1345}, 1 locked for N6
1i. 11(4) cage at R2C9 = {1235}, 1 locked for N3

2a. 45 rule on N1 2(1+1) outies R1C4 + R4C1 = 16 = [79/88/97]
2b. 29(4) cage at R2C1 = {5789}, 5 locked for N1
2c. 15(4) cage at R1C2 = {1239/1248/1347} (cannot be {2346} because R1C4 only contains 7,8,9)
2d. R1C4 = {789} -> R1C23 + R2C3 = {123/124/134}, no 6, 1 locked for N1

3a. 45 rule on R789 3 outies R6C159 = 21 -> R6C1 = 5, R6C59 = 16 = {79}, locked for R6
3b. Naked triple {123} in R7C12 + R8C1, locked for N7
3c. Naked triple {789}, locked for C1
3d. R3C2 = 5 (hidden single in N1)
3e. 11(4) cage at R2C9 = {1235}, 5 locked for C9
3f. 45 rule on N7 1 remaining outie R9C4 = 3
3g. R9C4 = 3 -> R8C3 + R9C23 = 24 = {789}, locked for N7
3h. R7C3 = 5 (hidden single in N7)
3i. 14(4) cage at R7C4 = {1247/1256}, no 8, 1,2 locked for N8

4a. 45 rule on N9 2(1+1) outies R6C9 + R9C6 = 16 = {79}
4b. 27(4) cage at R6C9 = {3789/4689}, 8 locked for N9
4c. 17(4) cage at R8C7, R9C6 = {79} -> no 7,9 in R8C7 + R9C78
4d. Naked triple {789} in R9C236, locked for R9, 8 locked for N7
4e. 17(3) cage at R7C7 = {179/269/467} (cannot be {359} because R9C9 only contains 1,2,4,6), no 3,5
4f. 1 of {179} must be in R9C9 -> no 1 in R7C7 + R8C8
4g. 5 in N9 only in 17(4) cage at R8C7 = {1259/1457/2357} (cannot be {2456} because R9C6 only contains 7,9), no 6

5a. 45 rule on C123 2 remaining outies R15C4 = 14 = [86/95], clean-up: no 9 in R4C1 (step 2a)
5b. 9 in C1 only in R23C1, locked for N1
5c. 15(4) cage at R1C2 = {1239/1248}, 2 locked for N1

6a. 45 rule on N3 2(1+1) outies R1C6 + R4C9 = 8 = [35/53/62]
6b. 27(4) cage at R1C6 = {3789/4689/5679}, 9 locked for N3
6c. 3 of {3789} must be in R1C6 -> no 3 in R1C78 + R2C7
6d. 5 of {5679} must be in R1C6 (cannot be 6{579} which clashes with 11(4) cage at R2C9 = {135}2), 6 of {4689} must be in R1C6 -> no 6 in R1C78 + R2C7
6e. 6 in N3 only in 15(3) cage at R1C9 = {267/456}, no 3,8
6f. 5 of {456} only in R2C8 -> no 4,6 in R2C8
6g. 8 in N3 only in 27(4) cage at R1C6 = {3789/4689}, no 5
6h. 3 in N3 only in R2C9 + R3C89, locked for 11(4) cage at R2C9
6i. 8 in C9 only in R78C9, locked for N9

7a. 45 rule on R123 3 outies R4C159 = 15
7b. R4C19 = [72/82/75/85] = 9,10,12,13 -> R4C5 = {2356}

8a. R1C5 = 5 (hidden single in R1)
8b. R1C5 = 5 -> R2C56 + R3C6 = 11 = {128/137/146} (cannot be {236} which clashes with R1C6), no 9, 1 locked for N2
8c. 5 in R9 only in R9C78, locked for N9

9a. 27(4) cage at R1C6 = {3789/4689}
9b. Hidden killer pair 8,9 in R1C4 and R1C78 for R1, R1C4 = {89} -> R1C78 must contain one of 8,9 -> R2C7 = {89}

10a. 7 in R1 only in R1C789, locked for N3
10b. 15(3) cage at R1C9 = {267/456}
10c. R2C8 = {25} -> no 2 in R3C7
10d. R1C23 = {12} (hidden pair in R1), locked for N1

[Looks like it’s time to start using forcing chains. My first try with R1C6 failed on one path, then I found step 11b.]
11a. R1C4 + R4C1 (step 2a) = [88/97], R1C6 + R4C9 (step 6a) = [35/62], R2C56 + R3C6 (step 8b) = {128/137/146}, R4C159 (step 7b) = [762/735/825]
11b. Consider placement for 2 in N2
R2C4 = 2 => R2C8 = 5 => R4C9 = 5 (hidden single in 11(4) cage at R2C9) => R4C15 = [73] => R1C4 = 9
or 2 in R2C56 + R3C6 = {128}, 8 locked for N2 => R1C4 = 9
or 2 in R3C45 => 20(4) cage at R2C4 = {2378/2468} (cannot be {2369} because R1C6 + R2C4 + R3C45 = {2369} clashes with R2C56 + R3C6), 8 locked for N2 => R1C4 = 9
-> R1C4 = 9, R4C1 = 7, R4C5 = {36}
[Cracked. The rest is fairly straightforward.]
11c. R2C7 = 9 (hidden single in N3) -> R23C1 = [89]
11d. R1C23 = {12}, R1C4 = 9 -> R2C3 = 3 (cage sum)
11e. R1C6 = 3 (hidden single in R1), R2C7 = 9 -> R1C78 = 15 = {78}, 7 locked for N3
11f. Naked pair {46} in R1C9 + R3C7 -> R2C8 = 5 (cage sum)
11g. R2C9 + R3C89 = {123} -> R4C9 = 5 (cage sum)
11h. R4C19 = [75] -> R4C5 = 3
11i. R9C7 = 5 (hidden single in N9)

12a. R1C4 = 9 -> R5C4 = 5 (step 5a)
12b. R8C6 = 5 (hidden single in N8) -> R6C5 + R7C56 = 23 = 9{68}, locked for R7, 6 locked for N8)
12c. R6C9 = 7, R8C9 = [98] (hidden pair in C9) -> R7C8 = 3 (cage sum)
12d. R9C6 = 9 (hidden single in N8) -> R8C3 = 9 (hidden single in N7)
12e. R3C9 = 3 (hidden single in N3)
12f. Naked pair {12} in R7C12, locked for R7 and N7 -> R8C1 = 3
12g. R9C67 = [95] = 14 -> R8C7 + R9C8 = 3 = {12}, locked for N9
12h. Naked pair {46} in R19C1, locked for C1
12i. Naked pair {46} in R19C9, locked for C9
12j. Naked pair {46} in R9C19, locked for R9
12k. Naked pair {12} in R17C2, locked for C2
12l. Naked pair {12} in R5C19, locked for R5

13a. 13(4) cage at R5C8 = {1246} (only remaining combination), locked for N6 -> R4C78 = [89], R5C7 = 3
13b. R1C78 = [78] -> 17(3) cage at R7C7 = [476], R1C9 + R3C7 = [46], R1C1 = 6, R8C2 + R9C1 = [64], R4C2 = 4, R2C2 + R3C3 = [74], R9C23 = [87]
13c. R56C2 = [93] = 12 -> R5C1 + R6C3 = 3 = {12}, locked for N4
13d. Naked pair {12} in R6C37, locked for R6

14. R2C56 + R3C6 (step 8b) = {146} (cannot be {128} which clashes with R3C45) -> R3C6 = 1, R2C56 = {46}, locked for N2

and the rest is naked singles.

Rating Comment:
I'll rate my walkthrough at 1.5 for my forcing chain.


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 Post subject: Re: Human Solvable 25
PostPosted: Sat Aug 15, 2020 11:37 pm 
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Grand Master
Grand Master

Joined: Wed Apr 30, 2008 9:45 pm
Posts: 693
Location: Saudi Arabia
To be honest Andrew this is more of an odd Assassin than a human solvable. I use two moves in the middle, then it was straightforward. They were:

1 a sort of IOU: r4c1 cannot be 9 as r1c4 and r4c4 would both be seven
2 I designed it so that 8-8 in the 16's and implied 12's would not work (this was as pointers at r5c5 would have to be 8 and also 4) and a medium looped conflict occurred if r4c1 was an 8


I will work on this format to create a true human solvable.


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 Post subject: Re: Human Solvable 25
PostPosted: Sat Aug 22, 2020 7:16 pm 
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Grand Master
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Joined: Tue Jun 16, 2009 9:31 pm
Posts: 280
Location: California, out of London
I always enjoy these HS puzzles. And this one certainly is. The only step that wasn't immediately straightforward in my solving path was to eliminate the impossibilities for the outies of r123. So I am somewhat puzzled what made this one difficult for the solvers. I should run one and see where it gets stuck :)


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