X is for indeX
by FullDeck and Missing a Few Cards Open on SudokuPad
Heartburn
- X-sums
- Indexing
- 1-5-9
The brief
Normal sudoku rules apply. Digits in red-shaded cells in column 1 indicate the position of 1 in the corresponding row. The same is true in columns 5 and 9 for 5's and 9's respectively. Clues outside the grid give the sum of the first X digits in the row or column from the direction of the clue, where X is the first digit seen in that row or column.