Six-grid Sudoku problem-solving skills The six-grid Sudoku problem-solving method is also applicable to nine-grid Sudoku.
First, the palace row method
Divide the number of a house by a certain number, so that only the last cell of the house is filled with a fixed number.
Second, the row and column exclusion method
Use numbers to exclude columns or rows so that the last cell of a column or row is filled with a fixed number.
Third, block exclusion method.
Use a number to indirectly exclude a house, and let the last cell of the house be filled with a fixed number.
Fourth, the only way
Observing the numbers contained in the rows, columns and palaces of a cell, it is found that only unique numbers can be filled in the cell.
Table 5-6 Sudoku Rules in Palace
The smallest unit of Sudoku, there are 8 1 * * in standard Sudoku. Row: A group of 9 cells in the horizontal direction. Column: A collection of 9 vertical cells. Palace: The area divided by thick black lines is a set of 9 cells in 3×3 in standard Sudoku. Known number: the number given by the Sudoku initial disk. Candidate number: the number that can be filled in each empty cell.
Formula and explanation of filling skill in palace lattice
1, wearing nine shoes, one, right three, left seven, two or four shoulders, six or eight feet.
Formula explanation: Usually 1-9 should be filled in the nine grids, so that the sum of rows, columns and diagonal lines is equal and the numbers are not repeated. In fact, there must be a formula when answering: 2 and 4 are shoulders; 6, 8 is enough; Up 9 down1; Left 7 right 3. As shown below: (2 9 4), (7 53), (6 18).
2. If you live in the middle of the rising line, don't forget to fill it in diagonally in turn. Put it down when loading and unloading boxes, and put the right box on the left when unloading boxes. The next box will be filled with the line weight, as will the top right line.
If you encounter nine consecutive numbers, you can also use this formula, such as 55, 56, 57, 58, 59, 60, 6 1, 62, 63, and put them in nine squares. We can regard the minimum number as 1, that is, 55 is 1 and 56 is 2.