Zhang Zhongyuan's expression was a little subtle, and he waved his hand and motioned for Chen Zhou to sit down.

Now, I robbed myself again......

After Chen Zhou sat down, he looked at Zhang Zhongyuan with interest.

He didn't think that if it was really as others said, Zhang Zhongyuan would have nothing to say.

Sure enough.

Zhang Zhongyuan coughed lightly, and then said: "Chen Zhou has explained to us in detail the significance of the number series verification method, and by the way, he also gave an example of the defects. ”

"However, just because it's flawed doesn't mean it's meaningless. ”

Zhang Zhongyuan's words also directly attracted the attention of all the students to himself again.

Seeing this, Zhang Zhongyuan smiled slightly, turned around and wrote a few words on the whiteboard [ignore even numbers and do not record].

It's just that, I don't know why, when he was writing these words, he suddenly thought of the topic discussion when Chen Zhou participated in the project for the first time.

Suppressing this inexplicable thought, Zhang Zhongyuan turned around and glanced at Chen Zhou before continuing: "Chen Zhou's example just now is a general term for even numbers, so what if we ignore even numbers, only for odd numbers, and verify them through the verification method?"

Hearing Zhang Zhongyuan's words, except for Chen Zhou, the other students fell into thought.

Zhao Qiqi, who was beside Chen Zhou, even turned his head to Li Li and asked, "If you simply verify the odd number, it seems to work, right?"

Li Li didn't speak, just crossed over to Zhao Qiqi and glanced at Chen Zhou.

Chen Zhou is naturally aware of this new verification method, but it also has flaws.

Chen Zhou has been looking at Zhang Zhongyuan, and he hopes to see Zhang Zhongyuan give a different way of thinking.

Zhang Zhongyuan picked up the wolfberry soaked on the table, took a sip, and glanced at the time by the way.

The time was just enough for him to finish this part, and by the way, he would spread the thoughts of his classmates.

Covering the cup and putting the quilt on the lectern, Zhang Zhongyuan said loudly: "Simply start from the odd number to verify, you need to consider the first odd number that is verified." ”

"It can be an odd number divisible by 3, or it may be an odd number that is not divisible by 3. However, after 3x+1, the second odd number is reached, and the third odd number, the fourth number, the fifth number, and so on. Every odd number reached in the whole process must no longer be divided by 3. ”

"However, if we start with the odd number that is divisible by 3, every odd number reached on the hail journey must no longer be divisible by 3, and can eventually be reduced to 1, then all odd numbers must be traversed. ”

With Zhang Zhongyuan's narration, the thoughts of the students who had just been pulled back fell into thinking again.

Chen Zhou still looked at Zhang Zhongyuan, he knew all these contents, and he was still waiting for Zhang Zhongyuan's next words.

However, Zhang Zhongyuan obviously grasped the time, and he did not immediately interrupt the thinking of his classmates.

Chen Zhou felt that someone had touched him, and he turned his head to look at Zhao Qiqi suspiciously.

Zhao Qiqi asked in a low voice, "Brother Chen, what does traversal mean?"

Chen Zhou was slightly stunned, and then explained: "Traversal is a concept of discrete mathematics, which refers to following a certain search route and making a visit to each node in turn, which is what Professor Zhang said. Well, there's this in my sophomore year, Data Structures. ”

"Oooh. Zhao Qiqi nodded again and again, slightly embarrassed.

He hasn't seen this textbook yet......

Chen Zhou's answer also gave an explanation for other students who didn't know the word traversal.

Naturally, they turned their heads to look at Chen Zhou again.

There is admiration and envy in the eyes.

Although I know that Chen Zhou is already a person who has taken the final exams of all grades of the Department of Mathematics, it is a different feeling to really feel this strong strength.

On the podium, Zhang Zhongyuan glanced at the time and said again: "I just said the odd number that is divisible by 3, and you must have thought of the odd number that is not divisible by 3. ”

"If we start with odd numbers that are not divisible by 3, then every odd number reached on the hail journey is also impossible to be divisible by 3, and they all end up being reduced to 1. ”

Speaking of this, Zhang Zhongyuan glanced at Chen Zhou again before continuing to say the following words: "In fact, in the process of verification, the odd numbers that cannot be divisible by 3 all have an infinite number of odd numbers from the previous step. ”

"Of these, about 1/3 of the proportion are odd numbers that are divisible by 3, and about 2/3 of the proportion are odd numbers that are not divisible by 3. And this phenomenon, you think, is very similar to what?"

As soon as Zhang Zhongyuan's words fell, Chen Zhou got up and said, "It's very similar to the situation of natural numbers. ”

Hearing Chen Zhou's words, Zhao Qiqi beside him instantly suddenly said: "Yes, it's very similar to natural numbers, why didn't I think of it?"

Li Li glanced at Zhao Qiqi: "Do you want to know why?"

Zhao Qiqi: "Why?"

Li Li: "Because you don't read as much as him." ”

Zhao Qiqi was stunned for a moment, he didn't understand the meaning of this sentence, he muttered: "You might as well say that I'm not as smart as Brother Chen......"

Li Li glanced at him and stopped talking.

On the contrary, it was the classmate in front of Zhao Qiqi, who turned around, looked at him with complicated eyes and said, "I think he may mean this......"

Zhao Qiqi: "......"

Zhang Zhongyuan raised his hand to stop the noise, and then motioned for Chen Zhou to sit down, and he took back what he just said: "What Chen Zhou said is very right, this phenomenon is surprisingly coincidental with the situation of natural numbers. ”

After speaking, he noticed that Chen Zhou was still standing there, so he asked, "Chen Zhou, do you have any questions?"

Zhang Zhongyuan's words also brought the attention of all the classmates.

Under the gaze of everyone, Chen Zhou said softly: "Professor, this new verification method has obvious flaws. ”

Zhang Zhongyuan smiled and nodded: "Well, tell me about it?"

Zhang Zhongyuan's thoughts at the moment are that this small class class can be regarded as all out of the limelight by this kid.

However, he didn't care.

After all, Chen Zhou has always been a student he values very much.

What's more, this kid is very similar to the young him......

Chen Zhou didn't think so much, and said directly: "The operation of this verification method is not continuous, and it is very troublesome in the process of verifying the climb or descent. When climbing, you need to factor 2, and when you descend, you need to calculate 3 to the Nth power. ”

After a pause, Chen Zhou continued: "Of course, this method also has advantages, the advantage is that when it is verified to almost infinite climb, it can be directly replaced. Well, I'll give you an example. ”

When he heard Chen Zhou say that he would give an example, Zhang Zhongyuan's brows jumped, and he thought of the first topic discussion.

At that time, Chen Zhou also gave an example, which supplemented Shen Jing's research ideas......

However, Chen Zhou's voice pulled Zhang Zhongyuan's thoughts back to the classroom.

"For example, the verification process of 2n-1 multiplied by 2 to the 100 million power and subtracted by 1 is to replace 100 million 2s with 100 million 3s, that is, 2n-1 multiplied by 3 to the 100 million power and subtract one, through a one-time substitution, we need to calculate the 100 million power of 3. ”

"If you follow the traditional verification method, you need to multiply 2n-1 by 2 to the 100 million power and subtract 1 to calculate, and then calculate 100 million minus 1 step to get this result. ”

As Chen Zhou finished speaking, the bell rang outside the classroom.

Zhang Zhongyuan glanced at the time, it was almost over, Chen Zhou's performance was over, and he could leave class......

At the end, there was a reflection question of "summarizing the odd numbers divisible by 3 and the odd numbers that are not divisible by 3, and calculating them by the general formula", and the small class officially ended.