17.07.2012, 06:23
(15.07.2012, 12:34)Doczahni schrieb: ...
durch die Bücher zu den Deutschen- oder Weltmeisterschaften im Sudoku kenne ich nun schon einige Sudoku-Varianten...
Hallo Doczahni,
There are some possible strategies to follow. Like uvo has written, you can search for longer chains with dots between them. But if I prepare puenktchen sudokus, I often try to avoid those longer chains.
Second strategy: There are 4 even and 5 odd digits to use in sudoku. Next to every dot is one odd and one even digit. It's good to realise that.
Third strategy: if there is no dot, digits cannot be consecutive, like Dandelo has written. But beware: some of the older puzzles in the books you describe may have different rules. It's important to realise if all possible dots are in the grid or not. (It has to be written)
Fourth strategy: (based on the third) the 1 and 9 have only one neighbour. I sometimes use that. If a 2 is already placed and 1 can't be it's neighbour because there are no dots next to the 2 and there are some dots in the row/column/block where the 2 is placed, the position of the 1 can be very limited.
In the puzzle portal you can find numerous puenktchen sudokus. Some of them are pretty tough, but always solvable with the strategies that are described in this thread. Good luck!
PS: my answer is in English, since I am as Dutch as possible.