Logic Masters Deutschland e.V.

Draw a closed loop that travels along the edges of cells that does not touch or cross itself. Clues indicate how many times the loop visits the respective cells. In this context, a “visit” is defined as a contiguous section of the loop traveling on the boundary of the cell, including the possibility of just a single corner point; two such sections are considered separate visits if the loop leaves the boundary of the cell between them.

Blacken some cells in the grid such that all blackened cells form tetrominos, and no two tetromino shapes may repeat, including rotations or reflections. Tetrominos may not touch each other, even diagonally. If a cell with a clue is blackened, then that clue is ignored. Every tetromino must be placed outside the loop.

An example with trominos is provided:

SudokuPad

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