Riad's April Contest 2024 (13th - 21st April) Score Discuss
PR 2024 R4 - Word & Object Placement (26th Apr - 2nd May) starts in 40 hours 0 minutes Discuss
Diagonal Vision — LMI March Sudoku Test — 10th-12th March60 posts • Page 3 of 3 • 1 2 3
Should the diagonals be marked in the "Anti-Diagonal Sudoku"?
Will it be better if the diagonals be marked in the "Anti-Diagonal Sudoku"?
OptionResults
Yes, it will be much better8 Votes - [22.86%]
No / does not matter27 Votes - [77.14%]
View Results

@ 2012-03-16 9:00 PM (#6939 - in reply to #6938) (#6939) Top

Fred76




Posts: 337
10010010020
Country : Switzerland

Fred76 posted @ 2012-03-16 9:00 PM

Let's speak a bit about little killer:

Preliminary remark: The grid is constructed on the 6-cells diagonals !

Of course you can place digits on the 4 corners of the grid (I try to delete these clues, but I think it was hard enough with them ).

One can see the 6-cells diagonal with clue 48. That's the maximum possible. Cells have to contain 2 triplet 789. With these triplets, both 6-cells diagonal with clue 16 are then the minimum possible. So you can place pairs 12 and 7 in one box and a triplet 123 in the other box.
And finally, with these triplets placed, you can see that the last 6-cells diagonal, with clue 20 is now the minimum possible, with the sum of two 145 triplet which can be placed.
One fun placement now is the 2 in the middle of the grid (fun because it's rare to be able to place a digit in the center of a little killer in the beginning of the resolution).



(littlekillera.png)



(littlekillerb.png)



(littlekillerc.png)



Attachments
----------------
Attachments littlekillera.png (31KB - 0 downloads)
Attachments littlekillerb.png (34KB - 0 downloads)
Attachments littlekillerc.png (35KB - 0 downloads)
@ 2012-03-16 9:11 PM (#6940 - in reply to #6939) (#6940) Top

Fred76




Posts: 337
10010010020
Country : Switzerland

Fred76 posted @ 2012-03-16 9:11 PM

Finally (then I stop and let you concentrate on the tapa contest ), I want to speak about the diagonal twin sudoku.

There is (at least) 2 openings for these grids. You can begin with the corners. With grid A you can place 8 in R1C9, 4 in R9C9, and Grid B let you know the two other corners.

But there is another opening, which I find more elegant: You can start with the center of the grids: box 5. Grid A let you know that digits in white cells are 3,5,7 and 8. Knowing that individually they can't be placed in the same cell let you place the 5 in R5C6, the 3 in R5C4, then the 8 in R6C5 and 7 in R4C5 in grid B.
Then in both grids, 6 can be placed in R5C5, you have a pair 14 in cells R6C46, then 2 in R4C4 and 9 in R4C6.

Of course, you'll need still lot of work to solve these grids, but box 5 is almost filled



(diagotwin2.png)



Attachments
----------------
Attachments diagotwin2.png (18KB - 0 downloads)
Diagonal Vision — LMI March Sudoku Test — 10th-12th March60 posts • Page 3 of 3 • 1 2 3
Jump to forum :
Search this forum
Printer friendly version