Logic Masters Deutschland e.V.

After solving some excellent loop puzzles recently, I decided to also try this genre out and create a loop that chopped into small zipper line segments. Thanks Flinty, vitaminz and garford for testing and the detailed feedback.

• Normal Sudoku rules apply.
• Draw a 1-cell wide orthogonal loop which can't touch itself, not even diagonally.
  • Box borders divide the loop into segments.
  • Each segment has an odd length and acts as a zipper line.
  • Digits an equal distance to the center of a segment sum to the central digit.
• Digits in circles are on the loop and indicate the length of their segment.
• Digits in squares indicate how many cells they see orthogonally of their own "color" (loop/non-loop) including themselves. The other color blocks vision.

Example Puzzle

The images below show an example puzzle and the corresponding solution. The red line represents the loop which does not perform any diagonal movements (only moves orthogonally). The segments are represented by different colors. The long segment is a valid zipper line because 5=4+1=3+2. The 3-cell segment is valid because 4=3+1. One-cell segments are always valid zipper lines. All circles show the length of the segments. The squared two counts the number of visible non-loop cells. The squared 4 counts the number of visible loop cells. If the top-right digit of the puzzle was squared, it would have to be 6 because it sees itself, one cell to the left and 5 cells to the bottom.

Play the Example Puzzle on SudokuPad