Rubik's cube is a widely circulated mathematical game, which is said to have been discovered as early as Dayu's flood control. The magic square is characterized by an n×n square consisting of natural numbers, which is called an n-order magic square. The sum of the numbers on each row, column and diagonal is equal.

Robopard's specific method is as follows:

Put 1 (or the smallest number) in the center of the first line; Arrange the remaining n2- 1 numbers according to the following rules: 1) Put each number at the upper right of the previous number; 2) If the cell to put the number exceeds the top row, put it in the bottom row.

Or put it in the right column; 3) If the cell to put this number has exceeded the rightmost column, put it in the leftmost column and still put it in the previous row; 4)。

If the cell to put this number has exceeded the top row and the rightmost column, put it in the cell of the same column in the next row of the previous number; 5) If the cell where the number is to be placed has been filled in, the processing method is the same as 4).

Extended data

Thinking:19 =10,28 =10,37 =10,46 =10. If the sum of each logarithm plus 5 equals 15, it can be determined that the center grid should be filled with 5, and these four groups of numbers should be filled in the horizontal, vertical and diagonal positions respectively.

Fill in four corners first. If you fill in two odd pairs, then you may get an odd number, because the sum of three odd numbers. You can't fill in any odd numbers in the four squares. No If all four corners are a pair of even numbers and an odd number, that won't do either.

Therefore, it is decided that two even pairs must be filled in the four corners. After the numbers on the diagonal are filled in, the odd numbers in the remaining boxes are easy to fill in. The above solution is the simplest magic square, also called the third-order magic square. According to legend, when Dayu was in charge of water control, a "god turtle" with wonderful patterns appeared in Luoshui, which was called "Luoshu" in history.

With the current digital translation, it is the third-order Rubik's Cube. Yang Hui, a mathematician in the Southern Song Dynasty, summarized his construction method as: "Nine sons are arranged obliquely. It's easy to go up and down, but it's more important to be left and right. Four dimensions stand out. "