Vudoku

Vudoku is a variant of Sudoku puzzles where each cell must contain a number that satisfies additional rules.

Vudoku

Rules: In each cell of the 9×9 grid, enter a number in the range 1–9. Each number must appear exactly once in each row, column, and block.
Additional rules: The grid contains V-shaped corners, each occupying three squares. The number at the top of the corner must be equal to the sum or difference of the other two numbers on the sides of the V.