Sudoku advanced solutions, what are the Sudoku advanced solutions

The result of the indefinite integral is not the only derivative, and the verification should be able to improve the computational power of the differential first.

The basic rule of Sudoku is to fill in the numbers 1 to 9 in the blanks, so that each row, each column, and each intrauterine number is not repeated. Advanced Sudoku solutions include: remainder solution, intrauterine number pair placeholder method, number pair placeholder method in columns and columns, column block method and array placeholder method, etc.

1. Intrauterine number pair occupancy method.

The number pair placeholder method refers to making a certain two numbers only appear in a certain two grids in a certain area, although the position of these two numbers cannot be judged, but the placeholder of the two numbers can be used to exclude other numbers from appearing in these two grids, and then combined with the elimination method can indirectly fill in the next number.

2. Only the residual solution.

The remainder method is to use the possibility that there are only 9 numbers in each box in Sudoku, and if there are 8 numbers in a box that cannot be filled, only the only number that does not appear can be filled.

3. Row and column block method.

The column block method refers to the method of using row and column exclusion to create a block in a row or column, and use the block to delete the other cells of the block where the block is located.

4. Number pairs in the row and column occupancy method.

Number pair placeholder method, in the above palace number pair placeholder method, we have learned the number pair placeholder method, here is talking about the number of pairs appear in the rows and columns, at this time the difficulty of observation will be greatly increased, this technique is also one of the more difficult skills.

5. Array placeholder method.

The array placeholder method is a method that changes from two numbers accounting for two squares to three numbers accounting for three cells on the basis of the number pair placeholder method. The theory of technique usage is the same as that of number pairs, but the difficulty of observation has increased a lot.

Send out the Sudoku problem.

The details are as follows:

1. Joint division: find the same number in two rows of three diaphragms, and then use them to find the number of digits in another row. This method is suitable for intermediate and advanced Sudoku.

2. Patrol method: find out each diaphragm.

Digital frequency rental rate to find out where it is.

3. Exclusivity: This method is the key to solving the problem and is easy to be ignored by ordinary people. Observe the queue or diaphragm, and if there is a celebratory position that cannot be filled in by other numbers, fill in the remaining numbers.

4. Pending method: This method is not commonly used, but it is very effective. Temporarily locate a number in the region and use it for exclusion.

5. Row and Column Method: This method is used to improve the efficiency of solving problems by breaking the order.

6. Hypothetical method: As an expert, I do not advocate this approach.

7. Frequency method: This method is more effective than the previous method. List all the cases in the row or box, and then select a number with a high frequency.

8. Candidate algorithm to solve Sudoku problem with candidate method First, a list of candidates must be established. Under different conditions, each grid impossible candidate can be gradually and safely cleared.

The candidate number method can be used to solve complex Sudoku problems, but the use of the candidate number method is not as direct as the intuitive method, and it requires the preparation process of establishing a list of candidates, so the actual use can be solved by visual methods first, rather than by the candidate's method.

The solution to the candidate count method is the process of gradually eliminating unsuitable candidates, so you must be careful when deleting the number of candidates to determine whether the deleted candidates are safe, otherwise, the problem will have to be redone many times. With the help of PC software, the maintenance of candidate tables is made easy.

Conventional Problem Solving Techniques:

According to the process of problem solving, it can be divided into intuitive method and candidate number method.

The intuitive method is a method that observes clues directly from the pan potential of Sudoku without making any marks and deduces the answer.

The candidate number method is to delete the numbers that have appeared in the allele group cells, and fill in the blanks for the remaining fillable numbers as a reference for solving the clues, and the fillable numbers are called candidates (or alternative numbers).

The intuitive method and the candidate number method are only the difference between whether there is a note when filling in, according to personal habits, and are not the criteria for identifying the difficulty of the question or the difficulty of the technique.

1. Open Sudoku and select the high level of difficulty level.

2. Start the game to get the question.

<>4. Infer the remaining numbers in the same way.

5. After the initial simple inference is completed, if all the 3*3 small grids already contain a certain number, the number is completed and there is no need to continue to place.

6. When there is not a sufficient number of numbers prompted for screening, the elimination method can be used, for example, the two grids in the circle can be determined as a certain two numbers, then the other grids will no longer occupy the number, and the remaining numbers can be filled in the grid after exclusion.

7. If there is really no other number to determine, then you can use the exhaustive method to list and highlight the numbers that may exist in all the grids.

8. By observing the listed numbers, find out whether they meet the range of numbers in the corresponding grid.

<>10. If there is no number that can be excluded by continuation, the invocation method can be used backwards to select a number from the least likely grid.

11. Assuming that the number is correct, it is inferred whether there will be a repeat in the future, and if it does, it means that the previous choice is wrong, and another result can be changed.

12. Once you have determined the other correct number, start extrapolating from it.

13. Until all the numbers are inferred, crack the ashram level Sudoku level.