Dutch Flat Mates: Index Lines
- Indexing lines
The brief
Normal sudoku rules apply.
On an index line, the digit in the Nth cell along the line (starting from the diamond) indicates the position along the line where the digit N appears.
Eg: 3214 would be a valid line - the 1st digit, 3, indicates that the 3rd digit is a 1, and so on.
Dutch Flat Mates: Every 5 in the grid either needs a 1 directly above it or a 9 directly below it. It can have both, but it doesn't need both.