Let's solve Chess Sudoku Puzzle: King, Queen, Knight Sudoku.
Sudoku originally called Number Place is a logic-based combinatorial number-placement puzzle.
In classic sudoku, the objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 subgrids that compose the grid (also called "boxes", "blocks", or "regions") contain all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a single solution.
Completed games are always