Logic Masters Deutschland e.V.

Solve in SudokuPad

Sudoku: Normal Sudoku rules apply.

Walking Tour (German Whisper Loop):

• Draw a one-cell-wide loop through the grid.
• The loop moves orthogonally and does not touch itself, not even diagonally.
• Any two adjacent cells on the loop differ by at least 5.

Checkpoints (Seeing Circles):

• Circles within the grid are on the loop and count the number of cells in all four cardinal direction combined which they see on the loop, including themselves.
• Cells not on the loop block line-of-sight.
• Negative constraint: All possible circles are given.

• The view from a position outside the grid is such that each digit blocks line-of-sight to any smaller digit beyond them.
• Digits outside the grid count the number of cells seen in this way in their row or column.
• Yellow circles indicate that ALL the counted cells are on the loop.
• Red squares indicate that NONE of the counted cells are on the loop.