Whiskey Tango Foxtrot
(Published on 27. July 2025, 01:00 by XeonRisq)
The sections outside of the main grid is for Delta Sum clue values.
There doesn't seem to be an elegant way of notating within these sections, but center/corner marks can be used to identify sums.
For examples of how Delta Sums work, please refer to the example image posted on Delta Sums Intro.
- Normal sudoku rules apply.
- Delta Sums : A number outside the grid gives the sum of the differences between each pair of adjacent digits in that row or column.
- Delta Quads : A number in a circle at an intersection gives the sum of the differences between each pair of adjacent digits in the surrounding cells.
- Remote Sums : A digit X in a cage points to a second digit Y located X cells away in its row or column. The number in the top left corner of the cage gives the sum of X+Y. All Remote Sums point outside the grid at which point they will become a Delta Sum clue.
- SudokuPad link - link to solve puzzle below
The cage must point to the cell directly before row/column 1 or the cell directly after row/column 9.
Solution code: Row 4 followed by Column 6
Comments
on 30. April 2026, 22:21 by gfoot
Amazing, very fresh logic - I found it very hard for sure, it was challenging to think about the possibilities pretty much throughout the puzzle, but very satisfying to figure it all out!
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Appreciate the perseverance and glad you left the puzzle satisfied having conquered this beast. Probably one of the more difficult puzzles in my catalogue, kudos for solving it!
on 27. July 2025, 03:45 by War
Absolutely beautiful Logic, I think it's a 4 star challenge, but 5 star enjoyment. The logic of maximizing and minimizing the cages and delta sums flows great together. I'm not sure what you meant by "not elegant" there was some slight iteration, but not much.
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Really glad you enjoyed the puzzle.
The elegant comment was for the notation of the delta sums, not the puzzle itself. There seems to be no good way to place double digit values in Sudokupad, so corner or centermarks are all we have at the moment.
Appreciate the solve/feedback as well.
