## Weekly Assassin 13 25th August

Our weekly <a href="http://www.sudocue.net/weeklykiller.php">Killer Sudokus</a> should not be taken too lightly. Don't turn your back on them.
Andrew
Grandmaster
Posts: 300
Joined: Fri Aug 11, 2006 4:48 am
Location: Lethbridge, Alberta

### Weekly Assassin 13 25th August

Nice puzzle! Very challenging, I found it the hardest Weekly Assassin so far.

Here is my first ever attempt at a posted walkthrough.

1. R78C4 = {79}; R78C9 = {13}; 45 rule on C1234 -> R5C4 = 4; 45 rule on C6789 -> R5C6 = 7; 45 rule on N8 -> R9C46 = {13}; R78C6 = {45}; R789C5 = {268}

2. R1C34 = {59/68}; 45 rule on N2 -> R1C46 = 11; 45 rule on N1 -> R1C3 + R3C2 = 12; 45 rule on N3 -> R1C7 + R3C8 = 10; applying these four results together and eliminating identical digits in N1 and in N3 -> R1C46 = [56]; R1C3 = 9; R3C2 = 3; R1C7 = 1; R3C8 = 9; R23C4 = {18}; R23C6 = [92]; R123C5 = {347}; R456C5 = {159} with the 1 in R56C5 from 45 rule on R1234; R9C46 = [31]; R46C4 = {26}; R46C6 = [38] (cannot have both 8 and 9 in 19(4) cage); R9C3 = 6; 45 rule on N7 -> R7C2 = 4; R78C6 = [54]; R9C7 = 9; 45 rule on N9 -> R7C8 = 6; R6C78 = {57}; R4C78 = [61]; R8C5 = 6; R46C4 = [26]; R6C23 = [23]; R2C2 = 6; R5C1 = 6

3. In N3 6 must be in C9 and is blocked from R1C9 so R23C9 = [76]; 22(5) cage in N3 = {23458}; 26(5) cage in N9 = {24578}

4. In N7 3 must be in C1 and is blocked from R9C1 so R78C1 = {38}; 24(5) cage = {12579}

5. In N6 {49} must be in C9; R5C789 = {23} and either 8 or 9

In C1 9 must be in N4; R8C2 = 9; R78C4 = [97]; R9C8 = 4; R7C7 = 7; R6C78 = [57]; R2C8 = 5; R9C9 = 5; R8C78 = {28}; R78C1 = [83]; R78C9 = [31]; R9C12 = [27]; R78C3 = [15]; R79C5 = [28]; R23C1 = [15]; R23C4 = [81]; R2C3 = 2; R5C2 =1; R1C2 = 8; R3C7 = 8; R8C78 = [28]; R5C78 = [32]; R1C9 = 2; R1C8 = 3; R2C57 = [34]; R45C5 = {59}; R6C5 = 1; R5C359 = [859] ; R6C19 = [94]; R4C23 = [57] and so on

I expect that the more expert solvers will have found more concise approaches but hopefully this is worth posting.
Oscar
Regular
Posts: 28
Joined: Wed Jan 16, 2008 10:31 am
Location: Montesson
Clearly as time passes by "changes, everything changes" since I found this the most easy Assassin that I have solved! 18 months after the initial post of A13 the level of difficulty of the Assassins has definetly increased a lot.
Ruud wrote:After an easy start, prepare yourself to take two heavy barriers
The innies in most nonets did simplified the start, The barrier that I encountered was mainly in locating the forced singles, which accounted for a slow progress until the end. The snake shaped cages did fight until the end!
Solving time was slightly more than one hour.
I think this very good puzzle at a starting level.
Nothing can both be and not be