Rule system

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

A few classmates and I represented the 13th Middle School, participated in the'Youth Cup' organized by the Nanjiang Provincial Department of Education, and got the highest score in the final and won the'Youth Cup' champion.

This incident passed.

Not even a few people in the school talk about it.

I had no idea that someone would stand up and question my performance.

He is Jia Hongning.

The Rubik's Cube player of "Big Bang".

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

Everyone knows 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 said this not to win sympathy, but to stand up and say one thing: I said,'Jia Hongning won't win by force', not for emotional venting, but for evidence.

The evidence is in the show.

The current program recorded the Rubik's Cube used by Jia Hongning and Zhou Junkai in the test. In order to let the audience see it more clearly, the program showed the six sides of the Rubik's Cube before each test to show the fairness of the test.

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

This is what I call "evidence".

A 90-degree rotation of the fixed part of the Rubik's Cube is counted as one step, and the minimum number of steps required to solve the Rubik's Cube can be obtained.

The first round: Jia Hongning, 17 steps; Zhou Junkai, 22 steps.

The second round: Jia Hongning, 19 moves; Zhou Junkai, 24 moves.

The third round: Jia Hongning, 14 moves; Zhou Junkai, 23 moves.

If the fixed part of the Rubik’s Cube rotates once (including one hundred and eighty degrees) as the step, Jia Hongning’s three data are fourteen, sixteen and eleven;

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 the face of rigorous science and rigorous mathematics, I am sorry that the lawyer's letter does not work.

I repeat here again--

In the last issue of "Big Bang", Jia Hongning's Rubik's Cube competition was not triumphant!

...

It took Zhao Yi more than ten minutes to carefully compile the post, and then directly posted it, and then screamed in the group by advertising.

"My post! Cape Forum!"

"Please help!"

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

Gossip is only one aspect.

As a professional technical house, their hobbies are obviously different from those of ordinary people. Most of them just 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!"

Ma Xiaojun, a science missionary: "It doesn't seem to be difficult to design a program with a computer, right?"

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

Ma Xiaojun, a science missionary: "I do research and dive first."

Intelligent technology Zhang Junlei: "Why not just ask Zhao Yi?"

Science missionary Ma Xiaojun: "I am a Doctor of Science!"

Intelligent technology Zhang Junlei: "So you are embarrassed to ask a high school student? Can you understand it like this? Haha"

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

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

The point is!?

He is fighting with people, and things are making the hot search list. When people in the group see posts, how come they become technical discussions?

Fortunately, the people in the group are pretty reliable.

Everyone's focus is on algorithm communication, but I still help to forward it, and each of them has a certain degree of influence.

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

The message from the manager must be clear.

The science missionary Ma Xiaojun is a doctor of science who returned to China. He was hired by the Capital University of Technology as a lecturer. His position still bears the title of associate professor, and he is qualified to take 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, they also helped forward it.

Forward, forward again...

The post was connected to the Penguin group and quickly spread.

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

Click: 8267.

Reply: 249.

He began to watch the reply patiently.

Turn a page.

Turn another page.

Turn another page again.

The posts in the front row are almost all "technical exchanges", some are asking about algorithms, some are providing algorithm opinions, and some are disagreeing on algorithm opinions.

Then, the controversy began.

Zhao Yi flipped through more than a dozen pages and found that there are more techniques than gossip, but he did not post to discuss Rubik's Cube algorithm with others, but to prove that what he said was evidence and reason.

The direction of public opinion has been biased!

Fortunately, the gossip crowd is always the largest. Most non-technical personnel are not cold about the algorithm. They care about whether the conclusion is true.

As long as the conclusion is true, it proves that the game may be problematic.

Most gossip people think that if Zhao Yi dares to show the data, the conclusion must be true.

Science and mathematics cannot go wrong.

There are many replies to the algorithm controversy above, but no one said that the result was wrong, and a few others said that through imprecise estimates, Jia Hongning’s Rubik’s Cube is indeed less difficult to solve than Zhou Junkai’s.

...

Seeing this, Zhao Yi also found the problem.

The calculation of the Rubik's Cube with the fewest steps is not a simple matter.

Although he gave the answer directly, he couldn't give the calculation process. The process given in the "Law of Contact" is to use the simplest way to manually restore the Rubik's Cube, not how to calculate the lowest step.

"Do you want to take a video to prove it?"

This is feasible.

Just take a video of turning the Rubik's Cube, and use a fixed step to shuffle the Rubik's Cube with the six sides restored to become the Rubik's Cube in the show, which directly proves the conclusion.

but……

This proof is not rigorous.

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

Mathematics is rigorous, science is rigorous.

This is where the problem lies.

Zhao Yi searched for Rubik's Cube calculations, and soon discovered a bigger problem. The calculation of the minimum number of steps for Rubik's Cube has turned out to be a problem that has plagued the scientific community for decades.

The minimum number of steps to solve the third-order Rubik's Cube, there is a noun called-the number of God!

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

In 1992, the German mathematician Kossamba proposed a new idea of ​​finding a way to recover the Rubik's Cube, which greatly reduced the calculation amount of the Rubik's Cube.

Three years later, according to the method proposed by Cossamba, the scientist Reid inputted it into the computer for improvement. Through calculations, he found that the "number of gods" would not exceed 26.

However, Kossamba’s calculation method is not rigorous, and what he got from his thinking may not be the best way to restore it. Therefore, the calculation of "the number of God" is also very likely to be an overestimation.

However, without introducing Koshimba's ideas, the amount of calculation is too huge.

This problem has not been resolved.

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

"Nor!"

Calculating the minimum steps to restore a single certain Rubik's Cube, and calculating the'number of God', is not at the same level in difficulty. The different forms of the third-order Rubik's Cube are astronomical numbers--

43,252,003,274,489,856,000.

If only one of them is calculated, the difficulty is relatively simple and too much, but only using exhaustive algorithms, the amount of calculation is still quite huge.

That is definitely not desirable.

This is why there are many people discussing algorithms in the group and below the post.

Zhao Yi stared at the screen and fell into thinking.

If there is no effective, accurate, and publicly recognized calculation method, the results given in his post will be meaningless. At most, he will add a video to prove that he can indeed restore it in a fixed step.

But the other party still has something to say.

It is best to use a scientific and strictly prohibited method, so that the other party has nothing to say.

"Then design an algorithm and directly calculate, for each fixed form of Rubik's Cube, what are the minimum steps to restore!"

"If it can be designed, it's called a Rubik's Cube Calculator?"

"Just enter the color of the small grid on the fixed surface of the Rubik's Cube, and you can figure out how to use the fewest steps to turn the Rubik's Cube..."