Hello everyone, I am Zhao Yi, studying in Zhengyang No. 13 Middle School, and I am an ordinary high school student.

Together with several classmates, I represented the 13th Middle School and participated in the 'Youth Cup' held by the Nanjiang Provincial Department of Education, and got the highest score in the final and won the 'Youth Cup' championship.

This thing is over.

There weren't even a few people in the school talking about it.

I had no idea that anyone would come forward and question my performance.

He is Jia Hongning.

The Rubik's Cube player of "Brain Bang Theory".

I don't know why he said that, but when I was interviewed by a reporter from Nanjiang TV, I was very angry and said, "Jia Hongning's Rubik's Cube competition is not a good match." ”

We know what happened after that.

He apologized.

At the same time, he also publicly threatened with a lawyer's letter, saying that he would protect the legitimate rights and interests of himself and the program.

I don't say this to win sympathy, but to stand up and say one thing: I said 'Jia Hongning is not victorious', not to vent my emotions, but to prove it.

The proof is in the show.

In order to let the audience see more clearly, before the start of each competition, the program showed the six sides of the Rubik's Cube to show the fairness of the competition.

Although the picture is only for a short time, you can see it clearly if you look closely.

That's what I call 'evidence'.

Ninety degrees of rotation of the fixed part of the Rubik's Cube is counted as one step, and the minimum number of steps required to restore the Rubik's Cube can be obtained.

First round: Jia Hongning, 17 steps, Zhou Junkai, 22 steps.

Second round: Jia Hongning, 19 steps, Zhou Junkai, 24 steps.

Third round: Jia Hongning, 14 steps, Zhou Junkai, 23 steps.

If the steps are calculated by rotating the fixed part of the Rubik's cube once (including 180 degrees), Jia Hongning's three data are fourteen, sixteen and eleven respectively;

Zhou Junkai is eighteen, nineteen, and nineteen.

In each round of Zhou Junkai's Rubik's Cube, the minimum number of steps required exceeds Jia Hongning, in front of rigorous science, in front of rigorous mathematics, I'm sorry, the lawyer's letter doesn't work.

And I'll repeat it again --

In the last episode of "Brain Bang", Jia Hongning's Rubik's Cube competition was not a victory!

......

Zhao Yi spent more than ten minutes carefully compiling the post, and then posted it directly, and then advertised and shouted in the group.

"My post!

"Please!"

When the people in the group saw the message, they clicked on the connection and glanced at it a few times, and then they were attracted by the content.

Gossip is only one aspect.

As professional technical nerds, their interests and hobbies are obviously a little different from ordinary people, and most of them glance at the front and look directly at the final data.

The group soon became lively.

Intelligent technology Zhang Junlei: "This calculation is very complicated!"

Science missionary Ma Xiaojun: "It doesn't seem difficult to design programs with computers, right?"

Zhang Zhen, who is not a storyteller: "It's difficult, the data is too huge, I can't think of it in a short time." ”

Science missionary Ma Xiaojun: "I study and research, and I dive first." ”

Intelligent technology Zhang Junlei: "Why don't you ask Zhao Yi directly?"

Science missionary Ma Xiaojun: "I'm a doctor of science!"

Intelligent technology Zhang Junlei: "So you're embarrassed to ask a high school student?

Zhang Zhen, who is not a storyteller: "Don't always tell the truth, be hypocritical, be subtle, pay attention to subtlety!/ Haha"

Zhao Yi looked at the chat messages and felt a little helpless.

What's the point!?

He is in a war of words with people, and things have reached the hot search list, and when the people in the group see the post, how did it become a technical discussion?

Fortunately, the people in the group are quite reliable.

Everyone's focus is on algorithmic communication, but they still help to forward it, and each of them has a certain amount of influence.

For example, Zhang Zhen was directly sent to the company's group.

The message from the manager is definitely to the point.

Ma Xiaojun, a science missionary, is a returnee doctor of science, who was hired as a lecturer by Capital University of Technology, and his position also holds the title of associate professor, and he is qualified to lead graduate students.

He sent it to the student group.

Other people in the group who saw the news saw such a 'gossip' and 'technical' post, and they also helped forward it.

Forward, retweet......

The post was connected in the penguin group and was quickly spreading.

After Zhao Yi finished reading the chat in the group, he simply played the game, swiped the remaining 'leisure coins', and then returned to the browser to refresh the post, and found that it was already very popular.

Click: 8267.

Re: 249.

He began to look patiently at the reply.

Turn a page.

Turn another page.

Again, turn the page again.

The posts in the front row are almost all 'technical exchanges', some ask about the algorithm, some provide opinions on the algorithm, and some disagree on the opinions of the algorithm.

Then the polemic began.

Zhao Yi flipped through more than a dozen pages in a row and found that there was more technology than gossip, but he posted not to discuss the Rubik's Cube algorithm with others, but to prove that what he said was evidenced and justified.

The direction of public opinion has been deviated!

Fortunately, the gossip crowd is always the most, and most non-technical people are not interested in algorithms, they care about whether the conclusions are true.

As long as the conclusion is true, it proves that there may be something wrong with the game.

Most gossip people believe that if Zhao Yi dares to put the data out, the conclusion must be true.

You can't go wrong with science and math.

There are a lot of algorithm controversy reply posts on it, but no one said that the result was wrong, and a few people said that through not rigorous estimation, the difficulty of Jia Hongning's Rubik's Cube restoration is indeed smaller than Zhou Junkai.

......

Seeing this, Zhao Yi also found a problem.

The calculation of the Rubik's cube with the least number of steps is not a simple matter.

Although he directly said the answer, he couldn't give the calculation process, and the process given by the "Law of Contact" was to manually restore the Rubik's Cube in the simplest way, rather than how to calculate the lowest step.

"Do you want to make a video proof?"

It's doable.

As long as you shoot a video of turning the Rubik's Cube, the Rubik's Cube that is restored on six sides, and use fixed steps to disrupt it and turn it into a Rubik's Cube in the program, it directly proves the conclusion.

But......

This proof is not rigorous.

"Even if you shoot a video and manually restore the Rubik's Cube, it can only prove that the fixed number of steps can be restored, but it cannot prove that it is the lowest number of steps. ”

Math is rigorous, science is rigorous.

That's the problem.

Zhao Yi went to search for the Rubik's Cube calculation, and soon found a bigger problem, the calculation of the minimum number of steps in the Rubik's Cube turned out to be a problem that has plagued the scientific community for decades.

The minimum number of steps of the third-order Rubik's Cube is called--the number of gods!

The main reason for the emergence of the number of gods is that the calculation of the minimum reduction step of the third-order Rubik's cube is too large, and the probability of the steps is astronomical, which cannot be simulated by the computer, and it is impossible to give the accurate minimum reduction step.

In 1992, the German mathematician Kosenba proposed a new idea of finding a method for the restoration of the Rubik's Cube, which greatly reduced the amount of computation for the reduction of the Rubik's Cube.

Three years later, the scientist Reid entered the computer according to the method proposed by Koschenba and perfected it, and found that the "number of gods" would not exceed 26.

However, Kosenpa's calculation method is not rigorous, and what he obtains from his thinking may not be the best way to reduce it, and the calculation of the "number of God" is also very likely to be an overestimate.

However, without the introduction of Kosenpa's thinking, the amount of calculation is too large.

This issue has not been resolved.

Zhao Yi smiled bitterly and said to himself, "So, my brain can count the world's problems?"

"That's not right!"

Calculating the minimum step of a single definite Rubik's cube and calculating the 'number of gods' is not at all the same level in difficulty, and the different forms of the third-order Rubik's cube are astronomical--

43，252，003，274，489，856，000.

If you only calculate one of them, the difficulty is relatively much simpler, but the amount of computation is still quite huge by using only exhaustive algorithms.

That would certainly not be advisable.

This is also the reason why there are many people in the group and below the post discussing the algorithm.

Zhao Yi stared at the screen and fell into thought.

If there is no valid, accurate, and publicly recognized calculation method, the results given in his post are meaningless, and at most they will supplement the video to prove that they can indeed be restored in a fixed step.

But the other party still has something to say.

It is better to use a scientific and strict prohibition method so that the other party has nothing to say at all.

"Then design an algorithm and directly calculate what is the minimum step to restore each fixed form of Rubik's Cube!"

"If you could design it, it would be called a 'Rubik's Cube Calculator'?"

"As long as you enter the color of the small grid on the fixed surface of the Rubik's Cube, you can figure out how to use the least number of steps to rotate and restore the Rubik's Cube to ......"