Rules for Sudoku

The goal of Sudoku is to fill a grid so that each row, each column, and each subgrid contains all the unique digits. The size of the grid can vary (e.g., 9x9 or 4x4), but the rules remain the same.

Rows: Each row must contain the appropriate range of digits, with no repetition. For example:

• In a 9x9 grid, each row contains the digits 1 through 9.
• In a 4x4 grid, each row contains the digits 1 through 4.

Columns: Each column must also contain the appropriate range of digits, with no repetition.

Subgrid: The grid is divided into subgrids (e.g., 3x3 for a 9x9 grid, 2x2 for a 4x4 grid), and each subgrid must contain all the unique digits within the range, without repetition.