The reason for the total number of changes in the third-order Rubik's cube is this: after the six central squares are oriented, a coordinate system is formed. In this coordinate system, all 8 character blocks are arranged in 8! And each character block has three orientations, so it is 8! * 38, 12 prism blocks are all arranged, each with two orientations, that is, 12! *2 12, so multiplication is a numerator, and 3*2*2 on the denominator means to keep other color blocks still, and it is not allowed to change the direction of a character block, change the direction of a prism color block, and exchange the positions of a pair of prism color blocks or a pair of character blocks separately. As for why, I suggest you think about it first. I wrote some preliminary works. You can go here and have a look. It can be seen that with so many changes, it is not easy to change back to the same color in a short time. However, I heard that the fastest person in the world can restore a Rubik's Cube in 10.36 seconds (the record was set at the Belgian Open on February 24-25, 2007), and the record holder is Edouard Chambon from France. In fact, it is enough to learn the method. Why are those people so fast? Because he can remember many algorithms, or some are called formulas. To put it bluntly, it is a set of combined actions of turning left and right, so as to move a specific piece to the position you want or get a certain shape you want. It is said that the top players in the world can remember more than 600 algorithms. Here is the solution of the introductory Rubik's Cube. The so-called introduction means that the fewer algorithms, the better, because to be honest, if you don't play every day, the algorithm is easy to forget. This introductory Rubik's Cube tutorial involves few algorithms and is very simple. The whole process of six-sided restoration is basically easy to remember. Before we begin, I want to talk about the structure of the Rubik's Cube. I'm afraid some friends are not familiar with it. The relative positions of the six central squares of the Rubik's Cube are fixed. Take apart the Rubik's cube and you'll know this. I'm sure that when you start wriggling in the following way, it's easy to forget what color you started with, so you will be confused, so you must set a direction you like at the beginning. Here I choose blue as the top, green as the bottom, red as the front, orange as the back, white as the left and yellow as the right. Of course, your sticker may be different from mine. There should be 5*3 stickers on six sides of the Rubik's Cube! =30 kinds of stickers, why? Because if you specify the blue face as the top face, then the bottom face should have five options, and the remaining four faces form a ring, except for rotational symmetry, there are three! This is a paste method, right:) I chose the following picture. It will be slower to open the animation for the first time, and the animation behind it will open almost instantly. Clicking this button will pop up a window. This 3D graphic is made by java applet. If you want its source code, you can look here, thanks to Werner Randelshofer's excellent work. This animation is very simple and convenient to use. About Java applet for playing animation: If your machine doesn't have Java runtime environment installed, usually your browser will prompt you to install it. If for some reason, he doesn't prompt (Firefox usually doesn't prompt), but displays an X in the graphic position. Then you need to download it yourself from here: Java runtime environment (simplified Chinese version), or here (English version), or here (traditional Chinese version). If the above links are too slow, you can try Sina Download, Pacific Download and Silicon Valley Power Download. If you want to change the colors of six faces in all post-animation, you can set them here. Please choose a color from here, and then click the small box below to specify the color. Finally, it seems that there are too many words prepared. Everyone is bored. Let's talk about how to play the Rubik's Cube first. (Step 1) Make a cross on the first side to form the following appearance: Note that the edge and center of each side are the same color. There are many ways to do this step, so I suggest you play it freely. If it is really difficult, I provide a definite solution here, that is, change the blue prism color block to the bottom, then color the side and turn it up. Let me give you an example here. You should understand that for the position B in the left picture, of course, we can change it to the bottom in one step, but sometimes it will affect the aligned red face. You need to restore the position of the red face first, then align the side and turn the blue-yellow prism block up from the bottom. See the figure below for specific operation. The R2 180 animation of FDF will play automatically, or you can watch it step by step with the buttons on the right side of the play bar. Did I make myself clear? For positions A and C, you can rotate the surface to change it to position B or D. According to the above, you should be able to make a cross. Here I suggest a clear method for beginners. After our blue edges become the bottom surface, we can turn them up in no hurry. We can turn them into pictures on the left. Note that the four sides of the bottom surface can be in any order, which will reduce your difficulty. Finally, just open them one by one. Make animation according to the following steps of this method: Next, I will talk about marking. You may have noticed some strange letters in the last table. The meaning of those letters is simple. F = front, B = back, R = right, L = left, U = top, D = bottom. Take the marks in the above table as an example. F stands for clockwise rotation of 90, F' stands for counterclockwise rotation of 90, and R2 stands for right rotation180. In addition, if your Rubik's cube is a Rubik's cube with numbers, or a Rubik's cube with figures and patterns, then your six-sided central block has orientation problems. In this step, you can refer to this page to align the side center block. (Step 2) Correct the first side and add four sides to form a T-shape: in fact, you only need to learn one trick to do this step well. That blue character block, after turning around, has six positions.
For position A, we only need the following three steps, FDF', while for position B, it is exactly the same, that is, the first three steps are the mirror images of the top diagonal, and become R'd 'r'd 'r, as shown in the left figure, we will encounter the mirror images of the top diagonal countless times later, so please pay attention to the significance of this mirror image. (This animation is set to not play automatically, please press the play key to start. For positions C, D, E and F, you can always turn it to position A or B by rotating the side and bottom. Let's give an example: so the second step is completed and we have laid a good foundation. Say it simply. (Step 3) Put the prism block on the second layer and change its shape. It's still an algorithm, plus its diagonal mirror image, and it's done. This time we will turn the Rubik's Cube upside down, with the blue face down and the green face up, and the other faces will be adjusted accordingly. This is the algorithm. We need to change the red and white squares on the top surface to the position of the URU shown by the last number in the table. The whole algorithm is URU'R'+U'F'UF. Is it regular? Let's see, it seems that the second half of U'F'UF is just a diagonal mirror image of the first half of URU'R', right? We see that the first four steps of URU'R' are used to combine the two small blocks we want in the left picture, and the fifth picture marked red in the above table shows the combined two color blocks, while the last four steps of U'F'UF are used to fill the two small blocks we have combined into close to the correct position. So, what should I do if I encounter it? The answer is in the last paragraph. Our algorithm is a diagonal mirror image of the above algorithm, that is, the first half and the second half turn into U'F'UF+URU'R'U'F'UFURU'R'. In some cases, the prism you need is not on the top surface, but in the wrong position or direction on the second floor. What should I do? First of all, the prism block at the top you have to do will become top by itself. If they are still disobedient in the end, as shown in the left figure, we will use the above algorithm to get a prism block that has nothing to do with the whole situation, and the red and white prism block we want will naturally become above, which is a bit troublesome, but we can only bear it for our elementary solution, which may also inspire everyone to learn advanced solutions:) The effect is the same as the above algorithm. Please note that the starting states are not the same. And his diagonal mirror image: R U2 B U' B' U2 R'. At this point, the third step is completed. It seems that we have learned two algorithms so far. Come on.