Logic Masters Deutschland e.V.

This puzzle was created for zetamath's "Sortadoku" puzzle challenge for November/December 2023, where setters were tasked with creating a puzzle using sudoku rules...but with a slight twist. This may involve a little more than a "slight" twist, but I hope you enjoy it anyway!

Ratings, comments, and feedback are much appreciated! Please feel free to reach out to me on Discord if you have any comments or questions. Please also feel free to try my other puzzles here.

Rules:

• Place the digits 1-9 into each cell in the grid. Some cells in the grid are shaded, and all others are unshaded. Given digits may be shaded or unshaded.
• Digits in unshaded cells may not repeat in the other unshaded cells in their row, column, and 3x3 box (ie, they follow normal sudoku rules).
• Digits in shaded cells may repeat in other shaded or unshaded cells in their row, column, and 3x3 box (ie, they need not follow normal sudoku rules); digits in unshaded cells do not 'see' digits in shaded cells for purposes of sudoku.
• A digit in a cell with an arrow indicates the number of shaded cells in the arrow's direction; arrow cells are always unshaded.
• Clues outside the grid are both sandwich sums and shade sums.
• Sandwich sums indicate the sum of the digits in unshaded cells between the unshaded 1 and 9 in that row/column; any 1s and 9s in shaded cells would not be considered as sandwich 'crusts' for this rule.
• Shade sums indicate the sum of the digits in shaded cells in that row/column; for example, valid shade sums for a 3 clue include 3, 1+2, and 1+1+1.
• A row/column without a clue may or may not contain a valid sandwich; if a valid sandwich exists, the sum of the shaded cells may or may not equal the sandwich sum in that row/column.

SudokuPad: https://tinyurl.com/y8cv3hvv

Penpa+: https://tinyurl.com/yo2uw3eo