"Professor!"

"Your explanation was wonderful, every process was very careful, and there was no mud and water. Xu Mang said seriously: "I just came up with a problem, this problem requires a very solid mathematical foundation, as well as strong logical thinking ability, I hope you and the members of the team will try to do this problem." ”

"Huh?"

"Let me see. The professor asked curiously.

Words fall,

Xu Mang handed the paper in his hand to the professor.

A moment later,

The professor, who had a relaxed face, looked a little serious at this time.

"Ahem!"

"When did you come up with the question?" the professor asked with a serious face.

"Just now..."

"I came up with a random problem, this problem requires logical thinking ability..."Xu Mang said with a smile: "It is useless to have a solid mathematical foundation, if you don't have strong mathematical thinking, this problem is a little difficult to solve." ”

“...”

"Did you just come up with this question?" the professor was stunned for a moment: "Did you come up with it casually?"

"That's right!"

"Professor... Do you think this question is suitable for the contestants?" asked Xu Mang.

The professor nodded and said silently, "It's very suitable!"

"So..."

"I'll explain it first. The professor said, "And then let the participating students solve it, what do you think?"

"Oh. ”

Words fall,

Xu Mang sat back in the last row.

Looking at the back of this young man, the professor was a little curious, if all this was true, he did not lie, then his mathematical talent would be extraordinary, why did he not participate in the competition?

It's unreasonable!

That's it,

I'll ask later.

The professor began to solve Xu Mang's problem by himself, but he soon found out that although it was an algebraic problem, he couldn't find a breakthrough.

afterwards

The professor tried a complex solution, and it finally took seventeen minutes, and then extrapolated from the answer, and arrived at a relatively simple process, which happened to be the end of class at noon.

Seeing that Xu Mang was about to leave, the professor hurriedly stopped him.

"Classmates!"

"Wait a minute!" the professor shouted at Xu Mang, "Are you coming back in the afternoon?"

"Uh..."

"Come on!" Xu Mang nodded and said with a smile: "The professor has unlocked?"

"Unraveled. ”

"But I want to know what your answer is, and we'll talk about that in the afternoon. The professor said.

"Oh. ”

...

midday

Xu Mang and Yang Xiaoman were eating in the school cafeteria, and the five of them were full of curiosity about the conversation between Xu Mang and the professor, but no matter how they asked, Xu Mang always kept smiling and did not tell anyone about the matter between him and the professor, including Yang Xiaoman.

In this regard,

Yang Xiaoman was very unhappy and a little emotional.

Mostly a little humiliating ... It's obviously his boyfriend, but he keeps it a secret from himself... Still in front of so many people.

At a nearby Starbucks,

Yang Xiaoman ordered a cup of fruit tea and sat on the chair without saying a word, with the three big words 'unhappy' written on his face.

Yang Xiaoman: (# ̄~ ̄#)

“...”

"What?" Xu Mang played with his mobile phone, looked up and saw this scene, and asked strangely, "Who bullied you?" Beat him to a pig's head!"

Yang Xiaoman glanced at it and said angrily: "Then you can pump yourself yourself." ”

“...”

"So it's me?" Xu Mang suddenly realized, and said helplessly: "I'm quite honest today..."

"Humph!"

"You make it impossible for me to get off the stage in front of others. Yang Xiaoman said angrily.

Xu Mang frowned, counting the days... Today seems to be the day when Xiao Man comes to relatives, and he can't afford to provoke him... I suffered a big loss last time.

In the face of a woman who comes to relatives, the best solution is not to speak, and silently endure her little emotions, because at this time, no matter what you do, it is wrong, and there is no way... There are always a few days of the month when you are irritable.

crackling and complaining, Xiao Man got emotional relief.

"Xiao Man?"

"Huh?"

"Are you... Relatives here?" asked Xu Mang cautiously.

“...”

"It looks like I came in the middle of the night last night, and it scared the hell out of me in the morning. Yang Xiaoman suddenly asked with a mysterious face: "By the way, how do you calculate my life so clearly?

"Nope!"

"Hehe... Drink tea and drink tea. ”

soon

It's afternoon time.

Xu Manchong was at the forefront, happily came to the training classroom and found that the professor was already present.

"Hello Professor. ”

"Coming?" Seeing Xu Mang's arrival, the professor nodded and said, "Can you come and see my problem-solving process?"

"Oh..."

Xu Mang picked up the professor's problem-solving process, read it carefully, and there were basically no mistakes, and then said seriously: "Professor... You are a great name in the field of mathematics, absolutely right, and there are no mistakes. ”

"At first, I couldn't solve it, then I went around in a big circle, and finally I pushed it back, and I got this simplest process. The professor looked at Xu Mang and said solemnly: "I am impressed by your ability to solve questions!"

"Hehe..."Xu Mang smiled: "I'm just a student." ”

"What's your name..."

Halfway through the professor's speech, Yang Xiaoman and a few people came to the classroom, and the professor immediately did not continue, and said silently: "Let the contestants do the problem first, and then you personally help them analyze the process and solve the problem." ”

"Oh. ”

Xu Mang returned to his position in the last row and lay directly on the table.

"Ahem!"

"I'm going to give you an hour to solve a math problem!"

Words fall,

The professor wrote this question on the blackboard.

Use Z to express the set of all integers, find all functions f:Z → Z, satisfy that for any integers a and b, there are f(2a)+2f(b)=f(f(a+b))

At this point,

Everyone present was stunned, including Yang Xiaoman.

This...

What is this function?

afterwards

The five contestants began their own problem-solving process, but the process was very arduous because it was impossible to determine the form of the function.

Since they couldn't find the beginning, the five of them were almost simultaneously caught in a predicament where they couldn't move forward, and now they didn't even know what this function was, and they were even more confused and puzzled below.

Who gave this title?

Shoot him!

Wait a minute

In the morning... Looks like there's a guy who gets close to the professor, right?

At this point,

Everyone thinks of a person, and he is Xu Mang.

I'm afraid this question didn't come from Xu Mang, right?

The more I thought about it, the more I thought it was possible, otherwise Xu Mang wouldn't have discussed it with the professor for a long time, so angry... What the hell is he messing with?

Wrong!

Since this topic was made by Xu Mang... Isn't that his ability to do math already...

Thinking of this,

Except for Yang Xiaoman, the other four people gasped, this Xu Mang is so deeply hidden, I'm afraid he is not the real main player, right?

Unscientific!

Very unscientific!

Long

Five minutes passed,

The five of them were still in a state of confusion, they tried countless forms of functions, and still did not get any hope.

Ten minutes passed,

The five of them still have nothing to gain, and they begin to despair in the face of this function that can never be known.

Fifteen minutes,

Yang Xiaoman seemed to get some inspiration, and she began to write hard and make new attempts.

Forty-five minutes later,

The four of them were inspired and began to write hard, and Yang Xiaoman had just solved this problem, but the process was very complicated, and it took three blank sheets of paper to solve the problem alone.

ultimately

When the allotted time was over, the five turned in their answers to the professor.

Under the correction,

The professor found that only two people were correct, and only Yang Xiaoman was the closest to the reasonable process, but it was only the closest, and it did not fully meet its requirements.

Gap!

That's the gap!

At this point,

The professor called Xu Mang out of the corridor, he wanted to find out who this student from Fuzhou University was and why he didn't participate in the competition.

"Classmates?"

"You... What's your name?" the professor asked.

"Me?"

Xu Mang, a student in the Department of Physics at Fudan University. Xu Mang said with a smile.

“...”

"You are Xu Mang?!" The professor was stunned for a moment, and laughed: "I should have guessed that it was you, this was my mistake." ”

Words fall,

The professor suddenly straightened his face, glared at Xu Mang and said, "Why don't you participate in the competition?" If you are here, our ranking can still be raised, and the first place is not a problem, is it a retreat?"

"Nope. ”

"It was the tournament that banned me. Xu Mang sighed and said silently: "They said that I didn't meet the requirements and couldn't participate in the competition, but once I participated, the competition would become no suspense, so they directly banned me..."

Hear this,

The professor patted Xu Mang's shoulder and said helplessly, "I've started playing the so-called restriction trick again." ”

meanwhile

Yang Xiaoman is being bombarded indiscriminately by his teammates.

"Xiao Man, why is Xu Mang so strong?"

"yes... Why didn't he compete?"

"Are you timid?"

"How talented is Xu Mang's mathematical talent?"

Faced with a tidal wave of questions, Yang Xiaoman didn't know how to answer for a while, so he could only smile bitterly: "This guy is a... A clever. ”

In Yang Xiaoman's eyes, Xu Mang is a stupid person, so stupid that he can't describe it in words, because when they met for the first time, the image of a stupid person was deeply imprinted in Yang Xiaoman's heart, and he couldn't disperse for the rest of his life.

And smart... Needless to say.

“...”

“...”

“...”

This answer obviously does not meet the requirements of the four people, because this answer is full of love and is a bit suspicious of sprinkling dog food.

Then

The professor and Xu Mang walked in, the two stood in front of the podium, and the professor said: "I guess everyone has guessed that this question that stumped all of you was made by this classmate, and this classmate is from Fuda University, called Xu Mang, you should have heard of it." ”

"He has made extraordinary achievements in the field of physics, and has published two academic papers in SCI Zone 1. "But don't forget, Xu Mang's talent for mathematics is the same as his in physics," the professor said. ”

"Xu Mang?"

"Explain to them the solution to this problem, and by the way, I will also go to class. The professor smiled at Xu Mang, and then walked to the audience.

Yang Xiaoman was about to say that the professor... You'll regret it, but the professor walked straight off the stage without the slightest melancholy.

Looking at Xu Mang, who was smiling on the stage, Yang Xiaoman's head was bigger... Don't make your teammates autistic, it can't hurt!

"Students!"

"It's a very basic question, and it's not difficult at all. Xu Mang smiled and said, "This is a question to be sent!"

As soon as the voice fell,

The four students present were furious, and they were about to raise their knives.

At this point,

Yang Xiaoman: (°ー°〃)

Finished

He's going to start!

......