1. 1 19 What is the law of the nine squares?

From 1 to 9, the rule of Jiugongge is to live in the center of the rising line. Don't forget to fill it diagonally in turn, put it down when loading and unloading the box, and put it to the right when unloading the box. The next box is filled with row weights, as is the upper right row. This formula is not only applicable to jiugong, but also to odd jiugong in a broad sense, such as the five-five diagram and the seven-seven diagram. It is found that there is only one place where a number can be filled in a nine-square grid, which means that the filling position of the number in the nine-square grid is found.

1 to 9 The content of the Jiugongge rule

The first skill, know Jiugongge, the horizontal direction is vertical, the square of Jiugongge is a palace, and the numbers are different from each other until nine are together. This formula tells us the basic rules of Jiugongge. The horizontal direction is horizontal, and the horizontal number is 19, which is different. The numbers 1 to 9 in nine rows, vertical columns and vertical columns are different.

The second skill is to fill in a unique remainder, and there is one number left in the palace, so that you can pass the test, and there is one number left in the palace. This formula tells us that no matter horizontally or vertically, even in a palace, as long as there is only one number left, we should fill it in quickly, and we can get the corresponding answer quickly through gradual inference.

The third technique is the exclusion method, and there is a copy in each of the three rows and three columns. I have no choice but to misplace it. The exclusion method is that in the nine palaces, the vertical three palaces and the horizontal three palaces are taken as a whole, and each number of 1-9 can only appear three times in the vertical or horizontal column, and the number that has appeared twice can only be in a row or a column other than these two rows or columns. At this time, you can use it.

The fourth technique, the hypothesis method, has two kinds of numbers in the grid. If someone tries it, if the derivation is wrong, it will be swapped. If there is no wrong positive solution, all the numbers are tried in various ways. After filling in all the determinable figures, it is found that there are at least two possibilities for each position. At this time, we need to use hypothetical methods to help solve the problem.