Xueba starts with change

Chapter 679 Back to Research Status

"This thing, even if it solves the problem of the existence and mass interval of the Yang-Mills gauge field, it is still quite difficult..."

Looking at the research materials in front of him, as well as those new documents downloaded by Ding Ding Ding.

Chen Zhou couldn't help feeling a little dizzy.

This tough battle of gauge field theory is far more difficult than he imagined.

Even on top of the achievements that have been made, Chen Zhou is still not sure when he will be able to completely solve this problem.

After scanning the documents on the desk again, Chen Zhou got up slowly, ready to cook.

After touching the phone, Chen Zhou finally saw the message from Li Zhenbang.

Chen Zhou, who saw the news, unconsciously smiled.

It seems that Director Li is quite reliable?
Putting the phone away, Chen Zhou did not reply to the message, but sent a message to Chen Haining instead.

Chen Zhou told Chen Haining that he can let go of his hands and feet and do it boldly!
Regarding this, Chen Haining replied almost instantly.

The message wasn't even typed, just an emoji, a bared grin.

Seeing this expression, Chen Zhou felt that Chen Haining should be very excited.

Putting away the phone, Chen Zhou walked out of the room, called Chen Xiao and Qi Yin, and went to have dinner together.

Although it was past nine o'clock in the evening, Chen Xiao and Qi Yin were still waiting for Chen Zhou.

Chen Zhou was not very surprised by this. What surprised him was that Xiong Hao, the soy cow, hadn't come back yet.

If that's the case, isn't Qi Yin at night?
Thinking of this, Chen Zhou subconsciously took another look at Qi Yin.

Qi Yin felt something in her heart, and looked back at Chen Zhou.

Chen Zhou could only smile at Qi Yin embarrassingly.

Qi Yin suddenly became even more surprised. She didn't know what Chen Zhou was laughing at.

On the other hand, Chen Xiao, who was at the side, gave his elder brother a meaningful look.

I wonder if my elder brother is carrying his sister-in-law behind his back, do you have any strange thoughts?
"Ahem..." Chen Zhou coughed lightly to cover up his embarrassment, and at the same time asked, "Do you have anything you want to eat?"

Chen Xiao immediately said, "Eat whatever is delicious!"

Hearing this, Chen Zhou immediately turned his head and glanced at Chen Xiao: "Then what's delicious?"

Chen Xiao was at a loss for words for a while, but he just pretended to be very happy.

Regardless of Chen Xiao, Chen Zhou looked at Qi Yin again.

Qi Yin said indifferently: "I can do it."

Since both of them had no objections, Chen Zhou took them to eat his usual rice bowl.

The choice of rice bowl naturally attracted a lot of complaints from Chen Xiao.

It's a pity that Chen Zhou filtered it directly into the left ear and out of the right ear.

After dinner was settled, Chen Zhou began to seriously consider the issue of Qi Yin's overnight stay.

After all, this was the first time that a girl stayed in their dormitory.

Naturally, Yang Yiyi didn't count, she was the daughter-in-law of the old Chen family who was recognized by her parents.

Therefore, Chen Zhou had to think carefully about how to arrange it, and did he have to prepare something separately?
Also, are there any inconveniences that need to be informed to Chen Xiao and Cross in advance?
If the incident of Chen Xiaochen happened again, it would be embarrassing to the toes...

However, before Chen Zhou could speak, Qi Yin had already said: "Professor Chen, Xiong Hao probably will be back in 10 minutes. When he comes back, I will leave. The division of labor between me and Xiong Hao , remains the same as before.”

As soon as Qi Yin finished speaking, Chen Xiao turned to look at Qi Yin.

Then, he glanced at Qi Yin again.

This beautiful sister, is she leaving?

Then is there any chance, see you again?

It's a pity that Qi Yin didn't pay attention to Chen Xiao at all.

Naturally, he ignored the boy Chen Xiao, who had something wrong with his eyes.

Chen Zhou was stunned for a moment, then quickly realized, nodded and said, "Okay, thanks for your hard work, Captain Qi."

"Professor Chen, you are too polite. It is my duty to protect you." Qi Yin said with a smile, "Besides, didn't you invite me to dinner and take me to dinner again? It's hard work Fees are enough."

Chen Zhou didn't expect that this woman who was quite glamorous on the outside could actually make jokes.

However, Chen Zhou, who followed with a smile, didn't say anything more.

Not long after returning to the dormitory, Xiong Hao rushed back as Qi Yin said.

Qi Yin also successfully completed the "handover" with Xiong Hao.

After Qi Yin left, Chen Zhou went back to his room.

Sitting at the desk again.

Now, everything other than research is basically finalized.

Then he can return to the research state again.

After glancing at the research materials spread out on the desk, Chen Zhou started to sort them out.

At this point in the evening, he didn't intend to spend any more time on gauge field theory.

He is ready to formally start research on NP-complete problems.

After taking out a new stack of draft paper, Chen Zhou turned on the computer without any hassle.

Putting the draft paper aside, Chen Zhou logged on to major search websites and began to search for literature related to NP-complete problems.

Tracing the source and searching for inspiration through a large amount of literature is a research method that Chen Zhou has been accustomed to using for a long time.

It is also a process that Chen Zhou must go through when starting a new research topic.

After the download of the first document was completed, Chen Zhou moved the mouse and clicked on the document.

Then I brought the draft paper again, unscrewed the cap of the pen, and prepared to brush the literature.

NP-complete problems are also called NP-C problems.

is a non-deterministic problem of polynomial complexity.

The simple way to write it is "NP=P?".

The problem is just above the question mark.

In the end is NP equal to P, or NP is not equal to P.

Of course, almost the vast majority of people hope that NP is equal to P.

Because the actual meaning behind this is too important.

It's a pity that no matter how many people hope, they can't turn this millennium award problem into reality.

It still waits for someone who can solve it.

"The relationship between P-type problems and NP-type problems..."

At the end of the first document, Chen Zhou looked at what he had written on the draft paper, and murmured softly.

In fact, to know what kind of problem "NP=P" is, you must first know what is a P-type problem and what is an NP-type problem.

The two concepts of P-type problems and NP-type problems are related to the time complexity in computing theory.

As for the time complexity in computing theory, in simple terms, it is the speed at which the amount of calculation required for a certain algorithm to solve a problem increases with the scale of the problem.

This concept is more applied to computer algorithms in informatics.

In the algorithm, the time complexity essentially refers to the speed at which the amount of calculation increases, not the running time of the algorithm.

Naturally, for the same problem.

If different algorithms are used, their time complexity is not necessarily the same.

And if there is a certain problem, the time complexity of the optimal algorithm that can be found is a polynomial function of n.

Then, this problem is called a P-type problem.

P is the English acronym for polynomial.

In addition, there are some problems, regardless of whether they can be solved in polynomial time complexity, if you know a possible solution given at random, you can verify whether it is the desired solution in polynomial time complexity.

Then, such problems are called NP problems.

As for why to study a problem, is there an algorithm with polynomial time complexity.

It is because the growth rate of the calculation amount of polynomial time complexity is a bit too "fast".

As n increases, the amount of calculation is much smaller than the time complexity problems of O(2^n), O(n!), and O(n^n).

Just like the well-known large integer prime factorization problem.

Given a 2048-bit binary integer, find one of its prime factors.

Generally speaking, it may take hundreds of years of computing power to complete the calculation process.

However, if you know a certain prime number.

However, the most common computer can be used to determine whether this prime number is a factor of this 2048-bit binary integer within a few seconds.

And this is the difference between different time complexities in the actual calculation process!

Although sometimes it is not good to be faster, but in terms of time complexity, it is more valuable to be faster.

Naturally, all P-type problems belong to NP-type problems.

Looking at the content on the draft paper, Chen Zhou had already given this obvious explanation.

[A problem can be solved in polynomial time complexity, and of course it can be verified in polynomial time complexity. 】

However, Chen Zhou, who finished writing this line of text, added another "?" at the bottom.

Next to the question mark, Chen Zhou wrote: "What about the reverse?"

That's right, what about the other way around?
Can a problem that can be verified in polynomial time complexity be solved by an algorithm with polynomial time complexity?

Chen Zhou doesn't know yet.

Therefore, he drew two horizontal lines under this rhetorical question.

In fact, if this rhetorical question is asked, in fact, is it true that all NP-type problems belong to P-type problems?

And this is the famous NP-complete problem, that is, "NP=P?".

Although Chen Zhou still doesn't know the answer to this question.

However, Chen Zhou, who is no longer a novice in informatics, naturally knows the answer to this question and its practical significance.

If "NP=P?" there is no question mark.

That is to say, any NP-type problem that cannot find a P-type algorithm can find a corresponding P-type algorithm.

It also represents the prime factorization problem of large integers, which has become a P-type problem.

For example, a 2048-bit binary large integer can use an ordinary computer to complete the decomposition of prime factors in a few seconds or even less.

If this is the case, the RSA encryption algorithm, which is widely used now, will be completely invalid.

A large number of bank digital certificates and website SSL encryption will no longer be safe.

Those digital currencies that are hot today will also become mobile wealth that may be taken away at any time.

The entire digital finance will be reshuffled.

At the same time, if NP=P, it also means that a large number of problems that are difficult to solve through calculation will be easily solved through algorithm optimization.

Problems such as weather forecasting, traffic scheduling, protein structure prediction through amino acid sequences, the most efficient transistor layout on computer chips, etc., will all be solved.

It is no exaggeration to say that this is definitely a problem that changes the world.

Thinking of these, Chen Zhou didn't become so excited because of these practical significance.

He just looked away from the draft paper and turned back to the computer screen.

Then move the mouse and click on the second downloaded document.

The reason why Chen Zhou is like this is not that he has no vision of changing the world after solving this problem.

In fact, the difficulty of this problem is really a bit big.

Think about it and know, if it can be listed as one of the seven Millennium Prize puzzles, will its difficulty be average?
Moreover, from the current academic point of view, most scholars in related fields, including mathematicians, computational theorists, and senior algorithm researchers in informatics, etc.

All think that NP≠P.

The difficulty of this problem can also be seen from this.

In addition, the NP-complete problem is also different from the Yang-Mills gauge field existence and mass interval assumption problem that Chen Zhou solved quickly.

To a certain extent, this difficult problem is Chen Zhou's first research on a piece of uncultivated virgin land.

Therefore, Chen Zhou was not in a hurry to achieve success on NP-complete problems.

The time he gave himself was not too restrictive.

For now, Chen Zhou's research focus is still on gauge field theory.

For NP-complete problems, it should be ranked third.

The second place is Zhang Yifan's research on the DMD-2 material.

As the documents were gradually downloaded, Chen Zhou stopped thinking about them, and instead immersed himself in sorting out the documents.

It wasn't until twelve o'clock in the evening that Chen Zhou recovered from his immersed research state.

After taking a look, there are still many documents being downloaded, so Chen Zhou simply screened them again, increasing the number of downloads again.

Then tidy up the materials on the desk, get up and go to wash and sleep.

Although he had no plans to retreat for research, Chen Zhou, who returned to the research state, also slowly returned to the previous research and life rhythm.

Early the next morning, before the alarm clock, Chen Zhou got up and went for a morning run with Xiong Hao.

After the morning run, I brought breakfast back to the dormitory.

After finishing breakfast quickly, Chen Zhou returned to the room and to the desk again.

Sometimes, Chen Zhou felt that this desk was his world.

The stacks of draft paper and the pen refills are his sharp weapons for conquest.

Chen Zhou, who entered the research state again, did not notice the passage of time at all.

And the next few days passed quickly between his pen and paper.

Until September 9th, the day Yanda starts school.

After Chen Zhoucai finished his breakfast, he didn't choose to return to his desk.

He planned to go to his office to communicate with his students.

Because in the past few days, he has received a lot of emails from these students one after another.

Although these students were all herded by him.

However, when the stocking is almost done, look at these children in general, how are they growing up?
Besides, Chen Xiao is going to report to Yanda Mathematics Department today.

By the way, this kid is going to move out of the dormitory and into the school's student apartment.

This was not Chen Zhou's request, but Chen Xiao's own decision.

Chen Xiao didn't want anyone to find out about his relationship with Chen Zhou.

Chen Zhou naturally had no objection to this.

He also wanted to see how far his younger brother could grow.

Just like that, Chen Zhou and Chen Xiao went out together.

　Thanks to book friend Yan Hongxue for the 100 starting coins!
　　
　
(End of this chapter)