Of course, Lin Xiao didn't bother to care what the people below him thought. He talked about himself. Whether the people below him could understand or not would depend on his ability.
Of course, some people's eyes lit up.
That’s right! The tolerance-exclusion principle!
Damn it, the boss is indeed a boss, his observation skills are too careful!
However, it was too early for their eyes to shine.
Because Lin Xiao's next step of using the principle of inclusion and exclusion made them all stunned, because this step was too complicated. If it were used by them, it would be difficult for them to use it even if they thought of it.
Of course, there are a few people who thought of using the principle of inclusion and exclusion, but they didn't know what to do after using it, and then they got stuck. So they looked at Lin Xiao's next steps and gradually admired them in their eyes.
Soon, Lin Xiao reached a similar point in writing, and then said: "According to the expression, we can use the parent function to do this recursion."
When they heard that we were going to use the generating function, the eyes of those few people lit up again, right!
Generating function!
Why didn't you think of it when you wrote it?
They were more and more amazed by it, and felt sincere admiration for Lin Xiao in their hearts.
In this way, Lin Xiao continued to write, talking about his own ideas while writing. The students who could keep up were immersed in the guidance of the god of study, while the students who could not keep up were already lost in confusion.
who I am?
where am I?
What heavenly book is written on the blackboard?
"It's a bit weird here. You need to use a cyclotomic polynomial. I don't know if you know it. It refers to the first integer coefficient polynomial of the smallest degree that satisfies a primitive unit root of degree n."
"Simply speaking, it means that in the factorization results of multi-realistic
Solution to the equation of 1.”
"This is a bit off-the-beaten-path, so it doesn't matter if people don't think of it."
"Then we will use the cyclotomic polynomial to scale to the end. There is still a little bit left here. We will continue to use inclusion and exclusion to split it into mod5. The result is multiplied by this matrix... and then the power of 2 becomes the gene function,
It’s almost out.”
“After you finally write it down, there are still some qualifications that you can’t forget to add.”
After Lin Xiao finished writing, the big blackboard was almost filled with his writing.
Looking back at the process, he saw that there were basically no problems, so he wrote down "Certificate Completed" in the last position.
"Ok, done."
Lin Xiao said, putting the pen aside, and couldn't help but sigh that this blackboard pen is still easy to use. If you use chalk, your hands will be full of chalk dust.
The students in the audience who didn't understand immediately applauded after hearing what Lin Xiao said.
Awesome 666!
Although we can’t understand anything, we can still call 666.
Of course, the few students who understood it were immersed in Lin Xiao's solution process, absorbing the knowledge that they had not mastered.
Some people have also taken out their notes and started to memorize it. Whether they understand it or not, Lin Xiao's answer process is worth studying. Maybe they will encounter this type of question again in the future?
Especially the second-place student Ouyang, who scored 11 points, felt even more impressed. He couldn't compare to this level. He even thought of studying with Lin Xiao.
So that Lin Xiao can guide him.
Chen Song, who was standing nearby and watching Lin Xiao, was not surprised by Lin Xiao's thinking process because he had already been surprised once when he looked at Lin Xiao's answer sheet.
But he was still shocked.
Because of the calculation speed shown by Lin Xiao when dealing with the parent function, even he himself could not achieve that level.
This part was the most complicated part of the question, and it almost reminded him of Ramanujan's formula.
The mother function itself is complicated, let alone this question. Even if you know how to use the mother function, you may not be able to calculate it from beginning to end. But Lin Xiao not only calculated it, but also did it so quickly that Chen Song
It can only be described as 'fast, accurate and ruthless'.
And what is the most important thing in mathematics?
In addition to those so-called mathematical inspirations, the second most important thing is to forget it.
Arithmetic is the oldest, most basic and most fundamental thing in mathematics. Just like the 'skill' in its name, it is a technology. The deeper you master this technology, the higher your attainments in mathematics will be.
sharp.
Just like Euler proved that the sum of all natural numbers is equal to -1/12, although the result is definitely wrong, creating the kind of proof that looks reasonable requires very sensitive computing power.
In the end, Chen Song could only lament in his heart that maybe some geniuses really find it difficult to use common sense.
So, he also applauded, then gave Lin Xiao a thumbs up, and said appreciatively: "Okay, Classmate Lin, very good, very good."
Lin Xiao smiled and nodded: "Thank you, teacher."
"Well, you deserve this. Okay, go down now."
Chen Song nodded, and then indicated that he had nothing to say to such a student.
Lin Xiao didn't stop for much, so he got off the stage and returned to his seat.
As he walked back, he could feel many eyes around him following his steps until he sat down.
He sighed in his heart, although he was happy that everyone was impressed by his talent, but why...
Isn't it because of his good looks?
Professor Chen Song is still discerning and capable, so he directly said that he is a handsome young man.
…
In the next course, Professor Chen Song explained the process written by Lin Xiao from the beginning. It was obvious that many students present did not understand it. After all, Lin Xiao was not a teacher, so he could not explain it to everyone.
Can understand, and this is the task of teacher Chen Song.
Of course, even for him, there are inevitably a few students present who still can't understand.
And even if you understand it, you will find that dealing with the parent function will make you feel overwhelmed. If you accidentally encounter problems, you can only go back and learn slowly.
As for Lin Xiao, hiding his merit and fame, he picked up abstract algebra again and continued to read.
…
Time passed quickly.
This morning's class ended just like that. After lunch in the school cafeteria, Lin Xiao returned to the hotel room.
As soon as he entered with his front foot, Kong Huaan also came in with his back foot.
Seeing him come in, Lin Xiao greeted him with a smile: "Have you had dinner?"
Kong Huaan looked at him squarely this time, and finally nodded and said, "Eat."
"What do you think of the canteen here? Is it delicious?"
"generally."
"I recommend you to eat their grilled rice on the second floor. It's not bad. It's reimbursed anyway."
"Um……"
It was rare for Lin Xiao to see this person say a few words to him. Lin Xiao felt a little surprised, but then he didn't say anything.
He was just being polite, raising his head and not looking down. Although Kong Huaan was a bit too introverted, he couldn't just ignore others. What if they felt that he was becoming more and more introverted by not talking to him?
?
A considerable number of young people today are like this and have a passive personality. However, a considerable number of people with this passive personality are eager to be noticed. However, their passive style always makes it difficult for them to really get attention.
, thus forming a vicious cycle, making them more passive and even inferior.
So I would like to say a few words to them from time to time to show that I have not ignored the other person, and maybe it can also help him mentally a little bit?
Of course, it was limited to the twelve days they lived together, but if Kong Huaan was escorted to Peking University and chose the Department of Mathematics, wouldn't they still have a chance to become roommates by then?
Thinking of this, Lin Xiao couldn't help but look at Kong Hua'an a few more times.
However, at this moment, Kong Huaan took the initiative and said to him: "I am actually... here to listen. My meal money cannot be reimbursed."
Lin Xiao was stunned immediately.
Is Kong Huaan an auditor?
This was a bit unexpected. I didn't expect that among the more than 20 auditors, I met one.
Then he smiled and said: "That's it, that's pretty good."
However, Kong Huaan asked at this time: "Will you... look down on me because of this?"
Lin Xiao was immediately speechless.
Little brother, it seems that your psychological problem is not ordinary and abnormal.