1936 year.

This year, the Olympic Games were held in Berlin, Germany. When bidding for this Olympic Games, Germany was still in the Weimar Republic, but by the time the Olympic Games were held, the mustache Hitler from "Hebei" had been replaced on the stage. Many people believe that the Olympics, a symbol of peace, should not be held in a Nazi country. However, a considerable number of people were still deceived by the Nazis who did not tear off the mask of hypocrisy at this time, and Hitler also secretly tried to use the Olympics to promote the "Aryan superiority theory" in preparation for the annexation of the world in the future.

At the same time, China also sent a delegation to the Olympics for the second time. Compared with four years ago, the attention paid to this Olympic Games has been greatly increased. Of all the sports, it is widely recognized that only the football team can still fight, because it swept the invincible opponents in Asia, which invisibly increased people's expectations. The All-China Sports Association has set up a football selection committee to select candidates for this football team from all over Asia, and issued a call:

"Whether at home or abroad, I don't ask novices or veterans, all my Chinese football players, so as to cover everything. In order to form a national elite team. Add glory to the Chinese nation. ”

For a time, North China, Shanghai, Hong Kong Island, the Dutch East Indies (present-day Indonesia), and Singapore ...... The selection competitions held by Chinese people everywhere to participate in this grand event are in full swing.

At the same time, on the campus of Fudan University, there is a "tiger" that has been dormant for a long time.

Sunday, April 19.

A football match is being played on the playground of Fudan University's Xincun. Fudan University team against the "Westerners United", a foreign team made up of some players who participated in the Scotto Cup. (Note: This cup is a famous football match in old Shanghai, which has been held for 40 years except for the two-year suspension of the Anti-Japanese War.) Most of the participants are "migrant workers" who come to China, and now there are also teams composed of Chinese. But the championship is basically monopolized by foreign teams. ）

Can the students not be enthusiastic? Since the return of "Instructor Lu" to Fudan, the Fudan school team, which has been repeatedly beaten by two sworn rivals, Shanghai St. John's University and Shanghai Jiao Tong University, has made rapid progress recently, which is jaw-dropping, especially the 6-2 victory over Shanghai Jiaotong University last weekend, which is really gratifying, and has a great sense of "the pattern of the ages has changed".

Therefore, although the price of this ticket is as high as "seven dimes" (the price of pork at this time is about two cents per catty), nearly 1,000 people still bought tickets to watch. Of course, Instructor Lu said that it is not mandatory to buy a ticket, and it is also welcome to come and cheer up the school team. He also used a fresh word called "cheerleading", which may have been imported from his study abroad in the East.

Fudan students can also play with regular team players, which makes people really respect Coach Lu's training ability.

However, at this moment, "Instructor Lu" is sitting in the audience, surrounded by a large group of students, and there should be no spare energy to pay attention to the performance off the field.

Almost every day, he practiced the Fudan school team in the playground, watched the school team training, and explained the high math questions to Fudan students on the side of the playground.

"Okay, the foreign football players we invited today are from four teams, and the stronger the team, the higher the appearance fee. Then let's assume that the appearance fee for each person in the Westerner football team is 5 yuan in silver, 3 yuan in the Xiyu football team, 2 yuan for the British Pelforth team, and 1 yuan per person for the British Agar team.

"Now, three games have to be played at the same time, and these four teams, with 44 players available, are playing against three teams, 16 players each, up to 48 positions, so how should these four teams be arranged to maximize their profits?"

On the "command platform" (rostrum), Lu Zhuhu held a pen in one hand and a thick notebook in the other, facing a group of Fudan students who listened attentively, and talked eloquently: "We can be sure that this is a linear programming problem, and the maximum profit can be obtained by making reasonable task arrangements for the existing players of the four teams." As for the idea, it is still the same as before, modeling to solve. Problem assumption, model establishment, model solving, result analysis, model evaluation, and finally model improvement......"

It has been a while since Lu Zhuhu traveled to the Republic of China (see the relevant chapters of "World Cup"), and during this time, time suddenly slowed down, which made him, who originally thought that he was just "visiting here", suddenly feel the reality and urgency of living in this undercurrent of the great era, which made him can't help but correct his attitude and think about what he should do for the Chinese people of this era as a "chosen child".

Football is his profession, foreign languages, mathematics, physics and chemistry, and he is also the best kung fu when he was in school.

But after thinking about it, I didn't come up with what role these few kung fu could play on the eve of Japan's invasion of China. In the end, I can only go back to Fudan University, where he taught with Li Huitang, the football king of the old Republic of China and vice president of FIFA, "more than ten years ago" (see the relevant content of the author's previous work "World Cup"), on the one hand, to train the Fudan football team, and on the other hand, to teach some of the things he has learned 70 years later to these "elites" now.

The reason why he mainly teaches mathematics, and also teaches English, French, Spanish, Portuguese, and Japanese, rather than physics and chemistry, which he is also good at, is because due to the current environment in China and the upcoming war, the environment in which these students engage in scientific research will undoubtedly be very difficult and lack of resources.

Mathematics, on the other hand, is the foundation of all sciences, the wisest and the gentlest.

Lu Zhuhu is always level-headed and speaks quickly, and he always wants to pass on to them what he knows the most in the shortest possible time.

Because, he had a hunch that he was running out of time to stay here.

"Okay, that's all for today. Next, if you have any questions, you can ask me. Lu Zhuhu closed the notes he had prepared today and entered the daily quick question and answer session.

"I have, I have!" The students chattered and shouted.

"Wow, Master Lu is worthy of returning from the First Imperial University of the East, and his insights are really novel!"

"Master Lu knows everything!"

Listening to the enthusiastic praise of the students, Lu Zhuhu couldn't help but blush a little at his lies.

He did study at the University of Tokyo.

But that was seventy years later.

If someone comes back from studying in the East and says they don't know him, won't the diorama be debunked?

Similar to later generations, people who are now studying in the West are also more highly regarded as if they were studying in the East. Fudan students will inevitably study in the United States and Germany in the future. However, after all, there is still a tradition of mathematics at the University of Tokyo, and there is nothing wrong with bluffing people.

The famous mathematician Su Buqing and him can be regarded as "the same teacher".

Taking advantage of the interval between explanations, Lu Zhuhu stretched out his head to take a look at the situation off the field, which was not bad with his own estimate-

The Fudan school team, which is committed to defense, makes the Westerners who are used to attacking and sending them not very adaptable, especially under the joint strangulation of multiple defensive players, it is difficult for the attacker's individual ability to be brought into play.

In the year when football played a super high score at every turn, the audience was very surprised when they saw that the score was still 0-0 when they played almost halfway, and they thought it was an invited opponent, and the "foreigner team" that formed a temporary team was releasing water.

In fact, this team is not weak, as Lu Zhuhu said, several players are players from the strongest teams in the "Skoto Cup".

Because the Scottto Cup is from autumn to spring, which has just ended, some players sometimes have itchy feet, and occasionally "fight" with Shanghai college students who are now in full swing in football.

Although the "Westerners" are also willing to "follow the local customs" and engage in friendly matches, the fact that they can agree so happily is also related to the generous and enthusiastic purchase of tickets by Fudan students, so they can get a lot of appearance fees. It's just that the foreign devils who originally just wanted to have fun were unexpected, and sometimes they had to be forced by this group of students to exert all their strength, causing the audience to cheer for the players of the school team.

Lu Zhuhu smiled with satisfaction, and stretched out his hand to take the next student's question, this student was very excited because he was picked by Lu Zhuhu first, it seemed that he was only sixteen or seventeen years old, but he didn't expect to go to college.

Lu Zhuhu glanced at the topic, thought about it for a while, and quickly wrote it in his notebook: "This question, you should do this-" On the paper, a line of words was also written:

T(a)=∑x=1Ne(af(x))

Enumerate, deduce, prove, all in one go.

The young man who asked the question looked at Lu Zhuhu's proof process, and then looked at the formula he wrote on the top, and read it several times before scratching his head and asking: "Uh, Mr. Lu, what is this-what theorem is this?" How come I haven't seen it? ”

"Fahrenheit's inequality!" Lu Zhuhu had already written down a series of numbers, and said casually. Speaking of Fahrenheit's inequality, he has a deep relationship with Hua Luogeng and his math teacher at the University of Tokyo. Therefore, Lu Zhuhu is very familiar with Fahrenheit's theorem.

But......

Lu Zhuhu suddenly suddenly realized that it was only 1936!

Fahrenheit's inequality was not published until 1938 by Hua Luogeng.

"It's me who crossed over!" Lu Zhuhu smiled bitterly, this is why he didn't dare to talk about protons, neutrons, quarks, and DNA double helixes. Because he was careless about some things that were already familiar in the later middle school textbooks, he did sometimes wonder which results were already available.

Mathematics is already the safest, but there are still occasional misses.

Blunder! Blunder!

It's a pity to write so much, but Lu Zhuhu still drew two bars, removed the Fahrenheit inequality bars, and said calmly: "I can't write this question." ”

Boy: "......" (You've written half a page...... ）

"Uh, Mr. Lu, you-think again? I'm not from Fudan, I'm from Jiaotong University, it's not easy to come here, they all say that you are amazing, I queued for a long time before it was my turn! The teenager was a little frustrated.

"Jiaotong University?" Lu Zhuhu raised his hand and flipped through the cover of the other party's exercise book, and suddenly saw the words "Wu Wenjun" written in the name column. He was taken aback and shouted, "Are you-Wu Wenjun?!" ”

Wu Wenjun was frightened by him, and said, "Uh...... Oh, yes...... Mr. ......"

"Then I can't teach you!" Lu Zhuhu shouted.

Joke! If this Wu Wenjun is Wu Wenjun, then he is the future great mathematician of China's Taishan Beidou level! Is this what I'm a half-person can teach?

It's no problem, he can prove Fahrenheit's theorem first, and then solve the problem - but doesn't this rob Hua Lao of the credit?

Lu Zhuhu was thinking wildly, and a group of students from Fudan had already squeezed Wu Wenjun aside: "We haven't lined up in the school yet, what kind of excitement are you doing at Jiaotong University!" ”

"That's it, your school just lost to us 2-6 last week, didn't you say that this shame is not snowy, and you won't enter the Fudan Gate!"

After all, Wu Wenjun was still a young man at this time, and he was a little angry, and shouted: "You will bully people!" If it weren't for the fact that my senior went to study in the United States last year, I would have asked him! ”

"Bragging! We've never seen anyone smarter than Master Lu! ”

"It's just that our professors are not as fast as Lu Shi to solve problems!" A group of Lu Zhuhu's little fans bragged shamelessly.

Lu Zhuhu was very interested, ouch, how good should it be to teach Wu Wenjun's senior, and asked casually: "What's your senior's name, it sounds very powerful." ”

"Qian Xuesen."

Lu Zhuhu: "......"