Logic Masters Deutschland e.V.

Duality

A Custom Variant Sudoku

by Alex Kilpatrick

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Rules:

• Normal Sudoku Rules Apply.
• Every clue outside the grid is two - and only two - of the following types of clues:
• A Sandwich Clue (indicates the sum of the digits between the 1 and 9 in that row or column)
• A Skyscraper Clue (indicates the number of cells in that row or column which do not have a higher digit between it and the clue)
• The Circle of an Arrow that extends at least one cell into that column or row (cells along the arrow must sum to the digit in the circle)
• The Bulb of a Thermo that extends at least one cell into that column or row (digits must increase from the bulb to the end of the thermo)
• It is not allowed for a clue to possibly be three types. For example, if a column has an outside clue of 3 and reads from that direction ?-5-1-3-9, the ? cell cannot be a 4 because then it could possibly be a Thermo, a Sandwich, and a Skyscraper clue; it must either be a 2 so that the clue is only a Sandwich and a Skyscraper clue or else from 6-8 so that it is only a Thermo and a Sandwich clue.

Example:

In this example, the clues that have been determined to be serving as Thermo and Arrow clues have been marked as such, the Skyscraper clues have been highlighted in yellow, and the Sandwich clues have been highlighted in red. The “3” clue in the top-left corner has not been marked since it has yet to be fully determined. However, the “3” clue has ruled out 4 as an option in R1C1, since placing a 4 there would cause the “3” clue to serve as three clue types.

Puzzle:

Solve it here:
- Penpa+ (with solve confirmation)
- F-Puzzles
- CTC App