Coordinate Arrows
(Published on 25. June 2025, 00:05 by phil_the)
The puzzle was written in response to one of Scojo's Setting Saturday prompts. This week Isaiah set the challenge to make puzzle using Coordinate Arrows which I had not seen before.
I decided to combine this with Sandwich sums which I am a bit more familiar setting with.
Each row, column and 3x3 box must contain the digits 1-9.
The sum of two digits along an arrow must equal the digit in the cell at row X, column Y where X is the first digit on the arrow and Y the second (arrow tip). No two arrows reference the same coordinate.
Clues outside the grid equal the sum of all the digits in that row or column sandwiched between the 1&9.
The two digits separated by a white dot differ by 1.
Solve in SudokuPadSolution code: digits in c3 from top to bottom
Comments
on 26. June 2025, 22:28 by dzamie
I don't often do well at sandwich puzzles, but this one had me going rather nicely back and forth between them and the arrows. The arrow uniqueness thing really helped both with break-in and with further along in my solve.
on 26. June 2025, 15:08 by phil_the
simplified the solution code
(When possible I try to use some aspect of the puzzle other than the resulting digits for the solution code. This is to try to discourage cheaters who just use the embedded solution to claim that they have 'solved' the puzzle. I assumed most people would colour the referenced cells as they find them, so wouldn't be difficult to identify the non-referenced cells.)
on 26. June 2025, 01:58 by Karitsu
The puzzle was a quick and delightful solve. The solution code took me about 8 hours :P
on 25. June 2025, 23:49 by dingledork
Fun puzzle; unnecessarily complicated solution code
on 25. June 2025, 21:14 by Exigus
I thought the two constraints worked very well together. Thanks!
on 25. June 2025, 18:46 by VitP
i thought this puzzle was intractable, and was about to rage quit. then i realized that i had missed the unique arrow rule.
typical.
anyone who reads the rules carefully will find the solve smooth and easy
on 25. June 2025, 10:16 by Srinidhi Kabra
Nice puzzle. Loved the way the sandwich sums give a unique solution at the end.
