Logic Masters Deutschland e.V.

This is my submission for the setting Saturday prompt by Scojo. The random constraint generator gave negators and sandwich. What a weird combination. Good luck!

• Normal sudoku rules apply: Place the digits 1 to 9 once each in every row, column and 3x3 box
• Column Indexer: The digit in column 9 indicates which position in that row the digit 9 should be placed. For example, if R1C9 were a 4, then a 9 would be placed in R1C4
• Sandwich: Clues outside the grid give the sum of the values sandwiched between the 1 and the 9 in that row or column. The X clue is the same in all cases, and its value is to be determined by the solver (it may be 0 or a double-digit number)
• Column Negator: Digits in column 5 are negative for the purposes of sandwich sums

Play on Sudokupad

Please provide constructive feedback especially if you found an issue with the puzzle. I want to improve. You can see my intended solve path (PDF)