# Sudoku

The origin of Sudoku can be traced back to the 18th century when the Swiss mathematician Leonhard Euler proposed Latin squares. It later evolved into a number puzzle game developed by an American mathematician and eventually became the Sudoku game we know today in Japan.

The rules of Sudoku are simple, yet the solving process is intriguing, requiring players to engage in logical reasoning. It serves as an excellent brain-training game.

## How to Play Sudoku?

The rules of Sudoku are as follows:

- Each Sudoku game consists of 9 3x3 grids, with each grid further divided into 9 cells, totaling 81 cells.
- Each cell contains a number from 1 to 9, with each number appearing only once in each grid.
- Numbers within each grid must be unique.
- Numbers in each row must be unique.
- Numbers in each column must be unique.

You need to fill in the numbers in each cell according to these rules to ensure the entire Sudoku grid adheres to them.

The solutions to valid Sudoku puzzles are unique, so you must carefully deduce which numbers to fill in based on the given clues.

We have prepared "Beginner" difficulty levels for newcomers to familiarize themselves with the rules. As you progress, you can gradually increase the difficulty!

## Instructions for Playing Our Sudoku Game

Below the grid, there are two rows of number buttons:

- The first row contains numbers from 1 to 9, which are used to fill in the empty cells. Simply select the empty cell and then click on the corresponding number button.
- The second row is for making notes. When you're unsure about which number to fill in a particular cell, you can use this feature to jot down candidate numbers. It's a very useful function.

Below the two rows of numbers, there are some auxiliary buttons:

- The "Erase" button can remove the number filled in the currently selected cell.
- The "Hint" button can reveal the answer for the currently selected empty cell. You can use this feature unlimited times, but using hints will not count towards a "perfect solution."
- The "Complete For Me" button automatically fills in the answers for all empty cells. However, please note that automatically filled answers do not count towards the game's score.

We will keep track of your game statistics, including difficulty level, shortest completion time, number of puzzles solved, and the number of perfect solutions achieved. A perfect solution is achieved without using hints or the automatic solving feature and without making any mistakes.