After Rebirth, I Am the White Moonlight of All The Big Brothers

Due to the limited space of the whiteboard, the final steps presented are as concise as possible, so the thought process is ignored.

But anyone who has studied Olympiad knows that the steps of solving problems are only external appearances, and the real important thing is thinking ability.

Tan Jiaxu also wanted to hear how she solved the problem, how to get started, and how she came up with the lemma nesting lemma to prove the conclusion.

Jiang Fuyue: "Do you want to listen?"

"want--"

"it is good."

Tan Jiaxu returned to his seat and looked up at the podium. For the first time, Jiang Fuyue's eyes appeared squarely in his eyes.

Zou Hao was amazed.

Although Jiaxu usually plays with them and everyone has a good relationship, there is always a sense of pride in the genius.

He didn't show it on purpose, but Zou Hao could feel it.

Now, looking at Jiang Fuyue with this kind of eyes...

It can only be said that only the genius of the genius can convince the genius.

At this time, Jiang Fuyue had already picked up the pen and stood in front of the whiteboard——

"Seeing this question, many people's first reaction is to try to find the relationship between vertices and edges."

A large part of the students below focused their heads.

That's what they thought.

"We know a connected graph. Suppose it has V vertices. If there are only V-1 edges, it is impossible to have a cycle. Otherwise, the graph is not a connected graph."

"However, when we have V edges, a circle will definitely appear. On this basis, every time we add an edge, a new circle will be created. Suppose we have V+1 edges, the graph There is only one cycle in the graph, then when we remove an edge from this cycle, there will be no more cycles in the graph, but there are still V vertices in the graph, so there must be a cycle. So our assumption does not hold, the graph There are at least two circles in..."

Tan praised the focus.

Zou Hao didn't want to hear it at first, but the girl's voice was cold and cool, like a mountain spring in a deep stream, humming and ding dong.

He was attracted unconsciously.

Jiang Fuyue: "... A new definition needs to be introduced here, called margin, that is, the number of edges E minus (V-1), which is equal to E-V+1, is used to describe the excess vertices in a graph. quantity, and this quantity roughly determines the number of circles in our graph."

Tan Jiaxu's eyes lit up.

That's right, this is the step!

What he thought was how to bypass this proof point, but Jiang Fuyue directly introduced a new definition.

He avoids risk, and she rises up to it.

This is the difference in the thinking process of the two, which ultimately leads to the difference between success and failure.

Therefore, he lost, not without reason.

Jiang Fuyue stood on the podium, with a slender figure and outstanding temperament, but at this moment, almost everyone subconsciously ignored her appearance, and what they saw was her radiant wisdom, powerful logic, rigorous attitude, and her love for her. Knowledge of respect and piety.

"...If you think about it further, in fact, when there are more and more edges in the graph, there will be more and more circles, and these circles will intersect with each other, and the perimeter of the circles will become smaller and smaller. Going back to the question itself, The description of 'finite counterexamples' is used. If we want to solve this problem head-on, the only way seems to be to find such two circles constructively in an arbitrary graph..."

It turns out that someone's soul really shines.

So bright that you can't take your eyes off it.

Ling Xuan stood beside him and turned his head slightly, and this angle was just so that the students below could not see the obsession in his eyes at the moment.

His heart beat one after another, and the feeling so strong that it was about to burst through his chest made him both panic and excited.

He knew that some things could not be restrained.

For example, like.

But he didn't even have the courage to say it.

Jiang Fuyue is too dazzling.

He used to think that he was enough to focus on the light, but now he found that Jiang Fuyue itself was the light source.

Her excellence made him retreat, and her brilliance eclipsed everyone, including herself.

Wanting, but not daring, that unreachable tangle has become a kind of torture.

Ling Xuan lowered his eyes fiercely, he must be patient, he warned himself.

At this time, through the half-closed back door of the classroom, a person was also gazing at the radiant girl on the podium.

Jiang Fuyue: "...But the title also tells us that there are limited counter-examples to this situation, which is almost telling us that this way is not feasible. Then we might as well change the angle: prove the lemma, and use this lemma to lead to contradictions, Fulfilling counter-evidence..."

Qing Ling's voice reveals absolute rationality, supported by strong logic in the middle.

The man watched and listened, a smile slowly dipping in his eyes.

"Professor Xie?" Zhao Tiejun called softly.

Xie Dingyuan suddenly returned to his senses, but did not look back.

Zhao Tiejun took advantage of the situation and immediately smiled: "This is the Mathematical Olympiad class. Isn't it about to participate in the National League? It's training."

Xie Dingyuan is light.

Seeing that he was very interested, Director Zhao couldn't help but talk about sex: "The girl who speaks on the podium is the No. 1 in the third year of high school, and she is also the gold medal and special award winner of this session of IPhO and IOI. Both subjects are full marks, B and Q. Big good seedling..."

Speaking of this, Zhao Tiejun suddenly felt a sense of pride, and even his chest stood up.

"Really?" Xie Dingyuan answered lightly, giving him a chance to continue.

Sure enough, Zhao Tiejun began to talk incessantly——

"This child is very good, and none of the teachers in all subjects does not praise her for being smart."

Xie Dingyuan: Well, the brain is indeed more flexible, no matter whether it is studying or scolding others.

"I get along very well with my classmates. When I have time, I will give lectures to everyone, sort out the key points, and everyone will call her Sister Moon."

Xie Dingyuan: Sister? Obviously still a little girl.

"The sports performance is also outstanding. I have practiced high jump and shot put specially, and I often play basketball with my classmates after class."

Xie Dingyuan: Classmate? Male or female?

"Some time ago, I published a paper on the main page of the PRL journal. What's the title... um! I forgot, it's related to the movement of bacteria anyway."

Needless to say, Xie Dingyuan also knew.

Maybe he was the first to see the prototype of the paper?

"In short, Jiang Fuyue has an all-round development of morality, intelligence, body and beauty, and is a particularly outstanding student, a light in one!"

Xie Dingyuan couldn't help nodding, a smile flashed in his eyes, but he heard that it had already been said--

"...So, this lemma is as follows: for any positive real number a, natural number N, prove that for a proposition with N vertices, a graph with (1 + a)N edges has a cycle of length less than aN, and there are only a finite number of counterexamples... …”

Just listening to the sound made him feel good.

"The only thing that's bad," Director Zhao sighed, "is that his temper is a little stubborn and his ideas are bigger."

"Oh?" Xie Dingyuan raised his eyebrows.

"Some time ago, the recommendation notices from B University and Q University were sent to the school, saying that it was her major that she could choose at will. Unexpectedly, the child refused to refuse, and there was no room for turning around, and the parents also followed her."

Zhao Tiejun looked regretful.

That's big B and big Q!

I heard that that day, Xu Jing, Meng Zhijian, and Yu Wenzhou ran wild in the office, sighing and scolding.

And what about Jiang Fuyue?

She was stunned, and no one could persuade her to come back.

Xie Dingyuan heard it for the first time: "Why did she refuse?"

Zhao Tiejun: "It seems that you plan to take the college entrance examination?"

Speaking of which, he was a little proud.

Do students from other schools have the courage to reject B and Q universities?

No!

But they have one!

More than one!

Ling Xuan also refused, good guy, how can we get together?

This year is absolutely amazing!

Xie Dingyuan retracted his gaze, and took advantage of the situation to restrain the small smile on his lower lip: "Let's go, Director Zhao."

"Oh, ok, classmate Zhong's legs are pretty good, right?"

"Um."

"That's good, that's good. In fact, you don't need to make a trip in person, just make a phone call, or ask Zhong Zhong to bring a handwritten and signed note from your parents when he returns to school..."

It's better than coming in person, right?

In fact, Zhao Tiejun didn't know why the Buddha came suddenly.

When the school sent him to pick him up, he was stunned.

Xie Dingyuan stepped forward, and the voice of the girl behind him became smaller and smaller——

"Assuming that a graph has N vertices, at least (1 + a)N edges, and the lengths of all cycles in the graph are different, a contradiction needs to be constructed when N is large enough to prove that this assumption does not hold. Then we You can do this to find the shortest circle in the picture..."

When Xu Jing returned from a teaching and research meeting, he suddenly found that the atmosphere in the class was much more harmonious.

He asked the reason, who knew that these students were stricter than each other.

"?" Curious, scratching the lungs.

But he didn't struggle for too long, harmony is a good thing.

This friendly atmosphere continued until the end of the two-week semi-closed training camp.

Soon, the Olympiad National League is coming...

There is no reason, I just want to see my daughter-in-law.

Zhong Ziang: Use me as a pretense and want face?