Logic Masters Deutschland e.V.

Eleven Ns by Nathan Mays

Normal sudoku rules apply.

N-Sum Lines:
Gray lines can be divided into two or more segments that each sum to N. The solver must determine the value of N for each line.

Sandwich Sums:
A value on the outside of the grid indicates the sum of the digits between the 1 and 9 in its corresponding row or column. One of the sandwich clues is N. The solver must determine the value of N.

Inequality:
The arrow points to the smaller digit.

Global constraint:
All eleven values for N (10 lines plus 1 sandwich) are different, and must be from 10 to 20 inclusive.

This is my debut puzzle, so feedback is very much appreciated (good and bad).

I've had the basic idea with the 10 lines mulling in my head for many months now, until recently I decided on a way to incorporate the missing value between 10 and 20.

Not all of the "0" sandwich clues are strictly necessary, but in the end I decided to include them all because it looked interesting and it reduced some tedious bifurcation.

The inequality was obviously added in at the end for disambiguation. I'm not happy with that but sometimes that's just the way it is.