Run it Up the Flagpole
by FullDeck and Missing a Few Cards
- XV and number dots
- Whisper lines
- Modular lines
- German whisper
The brief
Normal sudoku rules apply: every row, column, and box must contain a complete set of the digits 1-9. XV: Digits separate by a V sum to 5. Digits separated by an X sum to 10. Not all possible or Vs are given (no negative constraint). German whispers: The green flag stripes starting in rows 4, 6, and 8 of the flagpole in column 1 are German whispers lines. Adjacent digits along these lines must differ by at least 5. Modular lines: The teal flag stripes starting in rows 5, 7, and 9 of the flagpole in column 1 are modular lines. Each set of three adjacent digits along these lines must contain one digit from each of the residues classes mod 3; that is, one digit from {147}, one digit from {258}, and one digit from {369}. The flagpole is a separate modular line.