159 Whispers
- Whisper lines
- Indexing
The brief
Normal sudoku rules apply.
Digits in column 1 indicate the column in which the digit 1 appears in that row (e.g. if r4c1 is a 6, r4c6 is a 1). The same applies to columns 5 and 9, with the digits 5 and 9 respectively.
Along green lines, adjacent digits differ by at least 5.