Logic Masters Deutschland e.V.

This puzzle is inspired by Subzero from Packattack25 and Schwupel. It uses yin yang shading to make part of the grid negative and allow for 17-cell renbans and 9-cell nabners. I recommend solving one of the example puzzles first to get a better feel for the ruleset.

• Normal 0-8 sudoku rules apply
• Standard rules for nabner- and renban lines apply
• Apply yin yang shading to the grid
• Shaded cells are considered negative for all clues
• Digits on renbans/nabners may repeat if they are shaded differently e.g. {-2,-1,0,1,2} would be a valid renban and {-2,2} would be a valid nabner.

Play Online: sudokupad (CtC), f-puzzles

Examples

In the first example puzzle the longer nabner line resolves to {3,-1,-3,1} and the renban resolves to {1,3,2,0,-1,-2}. You can play the example here

The second example maximizes the length of the renban by placing all digits except 0 twice on it. Notice that each digit that appears twice does so with two different shadings. You can play the example here.

A third example (without a spoiled solution) can be played here.

Long-form of the Rules

Included completeness and rigor. If you are attempting a puzzle of this difficulty, you probably will get along with the short form and examples above.

• 0-8 sudoku: Place the numbers 0 through 8 (instead of 1 to 9) in every empty cell. Digits may not repeat on a row, column or 3 by 3 box.
• Yin yang shading: Shade some cells in the grid such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected. No 2 by 2 area may be entirely shaded or entirely unshaded.
• Values/Digits: For unshaded cells the value of that cell is the digit placed in it. For shaded cells, the value is the placed digit multiplied by minus one.
• Renban: Values placed on a purple renban line form a set of contiguous integers in any order e.g.. {-2,1,0,-1,-3} would be a valid fill.
• Nabner: Values placed on a golden nabner line may not repeat and may not be consecutive e.g. if the value 0 appears on a line, the values -1, 0 and 1 may not appear anywhere else on the line.
• Shading amiguity: Since the only clues used in this puzzle are renban and nabner lines, it is not clear which part of the yin yang shading corresponds to positive and negative values. So in the exmple puzzles above the values of the green cells are either all non-negative (unshaded) or all non-positive (shaded).

Notes

Thanks for anyone who solved this and earlier versions (the version here the third iteration) on th CtC-fan-discord. Please leave a comment if there is anything unclear about the ruleset or if you have suggestions for better wording of the rules. I recommend solving this in sudokupad and not on f-puzzles, since f-puzzles won't allow you to place the digit zero.