How to Solve Nine Grid Sudoku

Commonly used methods to solve Sudoku include: observation, unique candidate method, elimination, recursive backtracking, repetitive reasoning and filling in the numbers.

1, observation method: first, carefully observe the sudoku puzzle, find out the numbers that have been given and the numbers that have been filled in, and understand the location of the spaces and restrictions.

2. Unique Candidate Method: For each space, according to the rows and columns where it is located and the numbers that already exist in the small nine-box grid, determine the number of candidates that may be filled into the space. If a number in the rows, columns or small nine-box grid can only appear in this one space, then the number is the only candidate, you can fill in the space.

3, exclusionary method: through reasoning and exclusion, narrowing the range of candidates for each space. Observe a row, a column or a small nine-box grid has been filled in the number, if a number of the only remaining unique space can be filled in, then the number can be filled in the space.

4, recursive back: when the candidate number method and exclusion method can not continue to move forward, we can try a recursive back method. Select a space, from 1 to 9 to try to fill in the number, and then go to the next space for the same attempt. If, after filling in a certain number in a certain space, you find that you can't complete the sudoku, backtrack to the previous space and try the next number. This recursive backtracking continues until all spaces are filled with numbers or until no valid numbers can be filled.

5. Repeatedly reasoning and filling in the numbers: Through the repeated use of the above methods, keep reasoning and filling in the numbers until all the spaces in Sudoku are filled in correctly.

It is important to note that the method of solving Sudoku puzzles may vary depending on the difficulty and complexity of the puzzle. More complex Sudoku puzzles may need to be solved by combining other reasoning techniques such as X-Wing, Y-Wing, Swordfish, and other advanced techniques. With practice and experience, you can gradually improve the speed and accuracy of your solutions.

What is Nine Grid Sudoku

Nine Grid Sudoku is a traditional logical reasoning game in which the numbers 1 through 9 are filled in a 9x9 square grid so that the numbers are not repeated in each row, column, and each of the smaller 3x3 nine-grid squares. Sudoku puzzles usually start with a partially filled-in number, and require the player to reason and fill in the remaining numbers based on the information available, ultimately completing the entire nine-cell grid.

The key to solving Sudoku puzzles is to use logical reasoning and elimination to determine the number of candidates for each space, and through continuous observation, reasoning, and filling in the numbers, gradually narrow down the range of candidates, and ultimately find the only solution. The rules of Sudoku are simple and straightforward, but vary in difficulty. Some Sudoku puzzles can be solved quickly, while others may require more reasoning and experimentation. Using solving techniques and persistence, you will be able to overcome the puzzles and enjoy Sudoku.