We’re running a small preview series on croco-puzzle for the 2016 WSC and WPC, which will take place in Slovakia soon. We’ll kick it off with an External Sudoku tomorrow. For this, I made an example puzzle which seems worth posting in its own right.

Rules Solve as a standard Sudoku, i.e., fill the grid with numbers 1-8 such that every row, column and outlined area contains each digit exactly once.

In addition, there is a diagonal rectangle of gray cells. Every edge of this rectangle must contain exactly the digits 1-(length of the edge). Diagonally adjacent digits in gray cells must not be consecutive.

Or see the instruction booklet.