Logic Masters Deutschland e.V.

Exploring the house numbering constraint, inspired by Jay Dyer's puzzle.

• Normal sudoku rules apply: Each row, column, and region indicated by thick borders in the grid must contain the digits 1 to 9 once each.
• House numbering: Shade nine cells, such that there is one shaded cell per house (row/column/box), and the digit in the first cell of each house gives the position of the shaded cell in that house. Each digit appears in exactly one shaded cell. Cell positions in boxes are numbered left to right, top to bottom.
• Renban: Digits along lines in the grid are a set of non-repeating consecutive digits in some order.

You can play this puzzle online using:

• CTC app (Sudokupad): https://tinyurl.com/fejvrpyx
• f-puzzles: https://f-puzzles.com/?id=29jcy6k3

Here's an example image how the 'house numbering' rule works:

Suppose that r6c5 is a shaded cell. Then the first cell of the column (r1c5) must be a 6, the first cell of the row (r6c1) must be a 5, and the first cell of the box (r4c4) must be an 8. The corner pencil marks in box 5 indicate how cells are numbered in boxes. This numbering works that way for every box in the grid.

Hope you'll enjoy.