Double Sudoku (Fun With Sudoku #7)

If you enjoy Sudoku variants that play with grid size and adjacency rules, you'll love this Double Sudoku. The puzzle is set on a rectangular grid where each row, column, and 2x4 region requires the digits 1-4 twice. The key rule is that no two identical digits can be adjacent horizontally or vertically. This creates a puzzle that is both a number placement and a spatial reasoning challenge, similar to a "no-touch" puzzle.

Double Sudoku is also known as Duo Sudoku. Now this puzzle type is appearing in WPF Sudoku Grand Prix Finals along with Classic Sudoku, Trimino Sudoku, Irregular Sudoku, and Palindrome Sudoku. All of the other types of Sudoku I have already published in this blog. This Double Sudoku I am republishing as the 7th Sudoku under the Fun With Sudoku Series, wishing all my friends who are part of this WPF final, Best of Luck for the finals.

Rules of Double Sudoku

Fill in the grid so that every row, every column, and every box 2x4 contains all digits 1 through 4 twice. Cells with the same digits may not touch each other, neither horizontally nor vertically.