Here is my walkthrough. I've edited it for clarity and added more notes of explanation based on comments received from sudokuEd. Thanks for those comments.
1. R34C5 = {12}, R67C5 = {34}, R5C12 = {89}, 7 in N4 locked in 20(3) cage which must have {49/58} in the other 2 cells with R3C2 = {89} to avoid clashing with R5C12, 45 rule on R123 3 innies R3C258 = 11 -> R3C2 = 8, R3C58 = {12}, 45 rule on N6 2 outies = 6 -> R7C8 = {45}, R5C12 = [89], R4C12 = {57}, 45 rule on R12 2 outies R3C19 = 8 -> R3C19 = [35] because the 21(3) cage in N3 cannot contain a 3, 45 rule on N4 2 outies = 10 -> R7C2 = 2
2. R3C34 = {47}, 45 rule on N1 2 innies = 16 -> R13C3 = [97], R3C4 = 4, 45 rule on N3 3 innies = 10 -> max 7 in each innie -> R3C67 = [96], 45 rule on N3 again 2 remaining innies = 4 -> R1C7 = 3, R37C8 = [15], R34C5 = [21], 2 in N4 locked in C3, 2 in N1 locked in C1 -> R12C1 = {26}, 10(3) cage in N1 = {145}, R12C9 = [79], 14(3) cage in N3 = {248}, R4C89 = {68}, R6C89 = [93], R5C89 = [41], R2C7 = 4, R12C8 = {28}, R1C2 = 4, R4C89 = [68], 14(3) cage in N6 = {257} with the 2 in R4C7, R67C5 = [43], R6C12 = [16], R456C3 = [432]
3. 45 rule on R89 2 outies = 11 -> R7C19 = [74], R7C67 = [69], R4C12 = [57], R89C1 = {49}, R7C34 = {18}, 45 rule on N7 3 innies = 11 -> R9C3 = {18}, 14(3) cage in N7 = {356} with the 6 in R8C3, R89C9 = [26], 45 rule on N9 3 innies = 15 -> R9C7 = 1, 18(3) cage in N9 = {378} with the 8 in R8C7, R79C3 = [18], R7C4 = 8
4. R1C456 = {156} so 6 in R1 locked in N2 -> R12C1 = [26], R12C8 = [82], R2C456 = {378}, 1 in N8 locked in R8 so R8C456 = {179}, R9C456 = [254] and carry on, the rest is simple elimination
Weekly Assassin 15 8th September
Weekly Assassin 15 8th September
Last edited by Andrew on Fri Sep 15, 2006 11:41 pm, edited 4 times in total.
mmm, something doesn't look right in Step 1 Andrew.
The next part of Step 1 is dependant on this elimination - so haven't gone any further into the walkthrough.
For r3c58 to be a Killer pair in r3, 1 or 2 must be in every combination in both those cells - but this is not possible since r3c8 can still be 4 or 5. So, I don't think you can eliminate 1 and 2 from elsewhere in r 3 at this point.R37C8 = {15/24}, Killer pair {12} in R3C58 so no other {12} in R3
The next part of Step 1 is dependant on this elimination - so haven't gone any further into the walkthrough.
As sudokuEd has pointed out, my original walkthrough was flawed. It would have been OK if the hidden split cage (is that an existing description or have I just made it up?) had been in the same row as the other {12} cell but doesn't work when the hidden split cage is at right angles to the row.
Thanks sudokuEd for pointing out the flaw in my logic. I'm happy to learn from my errors, hopefully it will make me a better solver.
I've now changed the walkthrough having hopefully found Ruud's combination to crack the safe. This doesn't depend on killer pairs in that row. Fortunately the changes only affect step 1 of the walkthrough.This Assassin is like a safe that requires the right combination to be opened. Should you fail, a timing device opens it after a week.
Thanks sudokuEd for pointing out the flaw in my logic. I'm happy to learn from my errors, hopefully it will make me a better solver.