Logic Masters Deutschland e.V.

For my second puzzle, I tried experimenting with X-Sums and Sandwiches. In particular, I wanted to combine these two constraints. So I started creating a sudoku to see what such a puzzle would look like, and I found the result very interesting. It was a lot of fun to make and I hope solving will be fun as well. I think the puzzle is quite hard if you're unfamiliar with these constrains but I recommend you solving the two warm-ups before to fully comprehend the constraints. Once you know the tricks, the main puzzle is much easier to solve.

Rules:

• Normal sudoku rules apply: fill each row, column and box with all digits from 1 to 9.


• X-sum clue: a black number outside the grid corresponds to the sum of the X first digits of its row/column where X is the digit that is closest to the clue (i.e. the X-Sum value for 346798152 is 13 from the left and 7 from the right).


• Sandwich clue: a grey number outside the grid corresponds to the sum of all digits between the 1 and the 9 of that row/column. On different grid sizes, the lowest digit and the highest digit are always the two sandwich bounds.


• X-Sandwich clue: a red number outside the grid is both an X-Sum clue and a Sandwich clue.

Please let me know if any rules need to be clarified or reworded so that I can make those changes as soon as possible. (I'm learning English in high school, I'm not a native English speaker)

Here are the two warm-ups:

Click here to play the 6x6 warm-up

Click here to play the 4x4 warm-up

And now the main puzzle:

Click here to play the main puzzle

Hope you enjoy it! Any feedback is highly appreciated!