After listening to what Wang Hao said, Zhang Zhiqiang stared at him for a long time and took a deep breath, but he had no idea what to express.
He silently returned to his seat.
After lighting up the computer screen, I typed four words on the search page - be at peace with the situation.
The explanation on the search page is, 'No matter what environment you are in, you can be at ease and content.'
Zhang Zhiqiang thought carefully about literary issues, "This word is used to solve research problems, which means not to take the initiative to think about it. When you encounter a special opportunity and think of a problem, just think about it. It doesn't matter whether you solve the problem or not."
.”
"So, this process will take a year or two, at least a few months? No matter how little, it will take ten days and a half, right?"
"Before class, I said I would just take things as they come, but after class I figured it out..."
Zhu Ping walked over silently and stared at Zhang Zhiqiang's screen, seeming to fully understand his feelings, and even put a hand on his shoulder.
Zhang Zhiqiang looked back with a sad face.
The two looked at each other and sighed in unison, "Alas!"
After Zhang Zhiqiang finished lamenting, when he looked at Luo Dayong's expression, there was no longer any "angry" expression, but his eyes were full of envy and jealousy.
That is a graph isomorphism problem, one of the NP problems!
The NP-complete problem, also known as "NP=P?", is one of the seven major mathematical conjectures of the millennium, and is the number one super difficult problem.
This issue is very complex.
P problems are easy to understand. They are problems with certain calculations. For example, addition, subtraction, multiplication and division can be deduced according to formulas, and the results can be obtained by calculation.
However, some problems cannot be calculated step by step.
For example, when looking for a large prime number, there is no formula that can deduce the next large prime number step by step.
The answer to this kind of question cannot be calculated, and the result can only be obtained through indirect 'guessing'.
For example, 7 is a prime number, which one is the next prime number? You can check 8, 9, and 10. None of them are prime numbers. Check 11 and find the prime number.
This is a non-deterministic problem. The result cannot be obtained through calculation, but needs to be verified one by one.
This kind of problem that uses the exhaustive method to get the answer is a complete polynomial problem. If you test it one by one, you can get the final result.
However, the complexity of such an algorithm is exponential. When the number reaches a certain level, the calculation will soon become impossible.
Some scientists have discovered that similar complete polynomial non-deterministic problems can be converted into a type of logical operation problems called 'satisfaction problems'.
Since all possible answers to this type of problem can be calculated in polynomial time, is there a deterministic algorithm for this type of problem that can directly calculate or search for the correct answer in polynomial time?
This is the famous "NP=P?" conjecture.
The above example of finding prime numbers is just the simplest NP problem.
In fact, NP problems cover a very large area and are an important direction of complexity theory. The "graph isomorphism problem" studied by Luo Dayong is one of the classic NP problems.
"Graph isomorphism problem" refers to the comparative calculation of complex networks.
For example, there are eight points on each side, and the point distribution is different. Each of the eight points is connected to at least one other point.
Because the distribution of points is different and the connections of each point are consistent, the drawn graphics will be very different.
So how to prove that the two graphics are completely consistent?
This is the graph isomorphism problem, which proves the consistency of two complex networks.
Luo Dayong had been researching for several years before, and had already found the direction and thought of a solution. What was missing was a 'flash of inspiration'.
Many studies will be limited to ‘this one foot’.
Some people are lucky and solve the problem suddenly when they think of it. Some people are unlucky and can't overcome it in their lifetime.
Wang Hao took a class and got some inspiration. He found a "way to take the first step."
After returning to the office in the complex building, Wang Hao began to talk to Luo Dayong. Even if it was a very important research, they did not find a private environment.
Mainly because of confidence.
The first self-confidence is that the people in the office are of good character and will not do anything to steal results or publish things in advance.
Second, it is impossible for anyone, including Zhang Zhiqiang, to understand the content.
Perhaps because the course he was teaching was "Nonlinear Functional Analysis", the method Wang Hao found was to start with the analysis of the entire system.
Starting from the analysis of the entire system, we slowly connected to each point, and then connected to Luo Dayong's research.
It sounds simple, but is actually very complicated.
Luo Dayong's level is quite good. Wang Hao only talked about the beginning, and he seemed to understand it a little. After listening to a short paragraph later, his eyes were already shining brightly.
"I see!"
"So it's so simple! Wang Hao, you are really a genius, such a genius. This method is so ingenious."
"I've never thought about it in this direction before."
Luo Dayong hugged Wang Hao excitedly. He noticed Wang Hao's indifference and said excitedly, "Maybe it's nothing to you, but to me, this is the result of several years."
"Thank you, Wang Hao!"
"Thank you!"
"We did this research together, and the credit for the results also belongs to you!"
Luo Dayong cried excitedly.
It is said that "a man never sheds tears". When you are determined to complete a result, especially when you see the results of several years of hard work, the excitement is something that others cannot experience.
So Wang Hao's expression was very indifferent. He was also happy for Luo Dayong in his heart, but he couldn't get excited at all. All he did was listen to Luo Dayong talk about his research. After understanding it, he went to a class and found the last word.
inspiration.
Zhang Zhiqiang and Zhu Ping were also very indifferent. They were also happy for Luo Dayong, but they couldn't help but think of Luo Dayong's words just now, "It turns out it's so simple."
Simple?
Zhang Zhiqiang just leaned over and listened a few times, and found that a lot of the content was beyond the scope of his knowledge.
Simple peat!
Needless to say, Zhu Ping didn't even move her steps, knowing that she couldn't understand.
Simple……
If anyone says this research is simple, I will go over and pull his hair out right away!
Zhu Ping stared at Luo Dayong's hair and suddenly felt her hands itching.
…
Luo Dayong's research has been completed. All that remains is to summarize the content, give a report at a mathematics conference, or write a paper for publication.
The news spread quickly.
Many people in the school came to visit after hearing about it. Several professors, directors and the like made a special trip to give Luo Dayong some advice.
For example, what academic conferences should I attend, what journals should I submit to, what is the format of the paper, etc.
Zhu Jianrong came here.
Chen Qinghua, the dean of the School of Computer Science, also made a special trip to talk to Luo Dayong for a long time to confirm that he had completed his research, and then said some words of encouragement.
The office in the complex is busy, with people coming and going all the time.
Wang Hao looked at the professors, directors, and leaders one by one, and felt a little bit like they were making a mountain out of a molehill. Even if they completed a large research, it wouldn't be like this, right?
When he saw that the school's vice-principal had made a special trip to encourage Luo Dayong, Wang Hao said to Zhang Zhiqiang with a corner of his lips, "Isn't this a bit exaggerated?"
Zhang Zhiqiang’s reaction was quite bland.
He looked at Luo Dayong with envy, then turned his head and said, "It's not an exaggeration at all."
"This is the correct way to achieve great results."
He nodded vigorously as he spoke, showing his absolute persistence in his opinion, "It's abnormal for you to publish a paper silently."
Zhu Ping and Yan Jing also came over and agreed with Zhang Zhiqiang's words, "That's right."
Yan Jing nodded, "That's true."
To be continued...