## What is Sudoku?

According to Wikipedia:

**Sudoku** is a
logic-based, combinatorial number-placement puzzle. 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 an example of a Latin square which include an additional constraint on the contents of individual regions. For example, the same single integer may not appear twice in the same row, column, or any of the nine 3×3 subregions of the 9×9 playing board.

## How to Play

As said above, the player need to complete the game by input number and every row, column and 3×3 block have unique 1-9.

## UI Control

- Use Arrow Key or pointer to choose the single cell.
- Input number by keyboard or the input pad shown on screen.
- Double Click to clear the block.