Sudoku Kingdom - Master Puzzle

Derived from the passion of intellectual games, dreamed of writing an interesting game, and the best way to learn and improve your skills in this classic puzzle game
Sudoku Kingdom was born that way.
About Sudoku Game: According to the wiki, sudoku (数 独) (originally called Number Place) is a quiz puzzle about the upcoming Sort numbers based on combinational logic.
The goal of the game is to fill the digits into a 9 × 9 grid so that each column, each row, and each of the nine 3 × 3 grid cells constitutes the main grid (also called "box", "block", or "region") contain all digits from 1 to 9. The puzzle control structure provides a completed grid Every well-established puzzle has a complete solution.