PS: Thank you very much for the monthly pass support of Yang Lizi book friends again. I am also very grateful to Xiaobai for the support of the two monthly passes, and I got good results in the final exam.

"Professor Liu Meng, please accept me. Han Yan said very firmly.

Liu Meng was originally not very interested in a student with a habit disease like Han Yan, who had a perfect score in the exam, and couldn't help his repeated insistence, and said after a moment's silence: " To be honest, I don't really like students like you, since you are so persistent, I will give you a chance, the most important thing to engage in scientific research is the ability to think like a mental illness, I will come up with a few questions to test your thinking ability, five minutes for each topic, if you can satisfy me, you are welcome to join my team, if you can't answer one of the questions, then I can only apologize. ”

Han Yan nodded firmly.

Liu Meng smiled: "Okay, then the first question will begin." ”

"How many times in a day do the hour and minute hands of the clock overlap?"

Han Yan's first instinct after hearing the question was 24 times, but he immediately thought that it shouldn't be so simple, so he used all his brains to calculate it.

When the minute and hour hands start to move from 12:00, the minute hand of the clock makes T turn in T hours, and the hour hand is T/12 turns, and when the two watch hands coincide for the first time, the minute hand is a full turn ahead of the hour hand, that is, T = T/12 + 1, and T = 12/11, that is, the watch hand overlaps for the first time at 12/11 (slightly later than 1:05). Replace the number of overlaps with N, and then replace T in the equation with 24. This results in: 24=2+N. Obviously, N = 22, i.e. the two watch hands overlap 22 times in a single day. They never coincide at 11 a.m. or p.m. Because they have to reach the 12 o'clock direction of the dial at the same time.

In just three minutes, Han Yan gave the answer, 22 times, at this time, many interested students in the audience were also calculating, but none of the students shouted stupidly after Professor Liu Meng gave the question 24 times, as a student of Shuimu University, this thinking ability is still there.

Liu Meng nodded. "Yes, I got the answer in such a short time, and this question is actually very simple. The difficulty lies in how to express specific problems in mathematical formulas, which is a kind of thinking expression ability, which is extremely important in high-level scientific research. Then the next question. Listen up. ”

"Crossing the bridge, four people need to get through a rickety suspension bridge at night. Unfortunately, they only had one torch, and the bridge was too dangerous for them to cross without the help of torches. Unfortunately, the bridge is not very strong, allowing at most two people to cross the bridge at the same time. The speed at which the four people crossed the bridge varied: 1 minute. 2 minutes, 7 minutes. 10 minutes. Obviously, the time it takes for two people to cross the bridge at the same time depends on the slowest person. So, what's the shortest amount of time it will take them all to cross the bridge?"

Han Yan's first idea was to use the fastest person to repeatedly cross the bridge to pick up and drop off others, so the time required was 2+1+7+1+10=21 minutes. It only took a few seconds to get the answer, and Han Yan immediately realized that this question might not be so simple, the shortest time must be less than 21 minutes, and there must be a faster way.

How should I cross the bridge? Han Yan's anxious mind was full of sweat, and the two people who had used it for the longest time must cross the bridge together, so as to save time, but if these two people crossed together, then it would take too long for one of them to send the torch to the other side, what should I do? Han Yan was very nervous, and at this time, his thinking had to jump and diverge, how to solve this problem? Can he leave a person on the other side of the bank in advance, Han Yan was overjoyed, and finally had an answer.

"Professor Liu Meng, the shortest time should be 17 minutes. Han Yan replied.

"Oh, tell me about the idea of solving the problem. ”

"Let's cross the bridge with 1 and 2 first. It takes 2 minutes. Let 1 come back with a torch. It takes 1 minute. Let 7 and 10 cross the bridge together, it takes 10 minutes. Let 2 come back with torches. It takes 2 minutes. Finally, let 1 and 2 cross the bridge together. It takes 2 minutes. The total time taken is 2+1+10+2+2=17 minutes. ”

"Hahaha, the thinking skills are really good. Liu Meng did not hesitate to praise Han Yan, and then said: "What can be seen from this question? Resources should be optimally cooperated, the person who crosses the bridge for the longest 10 minutes must be with a partner for seven minutes, in order to maximize the use of the ten minutes needed to cross the bridge, and those who spend 1 minute and 2 minutes belong to the excellent talents of colleges and universities, and they need to be used repeatedly. ”

Han Yan nodded thoughtfully, he realized that when Liu Meng gave him the question, he was also guiding his thinking direction, and he had already subtly changed his perfect score inertia.

Liu Meng suddenly turned his face and asked Hou Zhendao, "Professor Hou, don't you mind if I use your background to set a topic for Han Yan again?"

Hou Zhen also thought that Liu Meng was going to set a topic for the problems involved in his research direction, so naturally there was nothing to object, and he agreed very happily: "If Professor Liu Meng likes it, please do it." ”

"Then I'm disrespectful. Liu Meng replied with a sly smile, Hou Zhen faintly felt that it was inappropriate, and when Liu Meng said the problem, he almost ran away.

"The students all know that Professor Hou Zhen once had an affair, and just now Professor Hou Zhen agreed, and my question is: Does your husband have an affair? There are 100 couples in a small town, and they all abide by a strange custom: if the wife finds out that her husband has betrayed her, then she will kill her husband that night. The women in the small town know the secrets of other people's husbands, but they won't tell them. In other words, every woman only knows about the affairs of men other than her husband. Suddenly, one day the mayor announces that at least one man has cheated on his wife, assuming the mayor is telling the truth. Everybody believes what the mayor says, so what's going to happen next?"

Han Yan was confused when he heard this topic, and he couldn't grasp what the point of this topic was. In a hurry, we can only use exhaustive methods.

Let's assume that only one man betrayed his wife, and then the man's wife will suddenly find out that she doesn't know that any man is having an affair, while the other 99 women know that one man is betraying his wife, that is, the truth, and the only explanation for this is that there is only one man who has an affair, which is her husband. So she would kill her husband that night.

What if there were 2 men? There were 98 women in the town who knew the truth, but the other 2 women only knew that 1 man was having an affair. I can't say for sure if my husband is also having an affair. So on the day the mayor announced the matter, the whole town was fine. But on the second day, when the two women found out that neither of them had executed their husbands. will realize that more than one man has had an affair. That is, there are 2 men who are having an affair, in this case, one of them must be his husband. As a result, the two women would execute their husbands at the same time at night.

Han Yan's brain teaser was racing. And so on. Is it possible to conclude that if there were n unfaithful husbands in the town, they would all be executed on the nth night after the mayor's announcement?

When the time came, Han Yan was very unconfident to say his analysis, Liu Meng began to appreciate this student a little, although he had the inertia of the exam, his thinking talent was indeed amazing, and he intended to train him to join his team. He smiled at the moment: "Han Yan's thinking ability is indeed different, if it weren't for the fact that he spent too much time pursuing a perfect score in the exam. I believe that you have achieved extraordinary results, and I would like to tell you that sometimes even though there is only a small amount of information, if you analyze it carefully, you can still draw valid conclusions. In the past few years, I've been obsessed with game theory analysis, and here's the question I want to give you, of course, this question doesn't need to be answered on the spot, and if you have an answer, you can come to me alone tonight, how about it?

Of course, Han Yan is not admitting defeat, judging from the three questions given to him by Professor Liu Meng, Han Yan already feels that he has gained a lot, and the potential of his thinking ability has been squeezed out all of a sudden, so he nodded firmly.

Professor Liu Meng said: "Of course, if other students have any opinions, they can also ask me to discuss them, which is a very interesting divergent question. ”

The title goes like this.

There is an island with a tribe on the island, consisting of n=1000 inhabitants. There is a taboo in this tribe: they can't know the color of their eyes, they can't even talk to each other about it, if a tribesman knows the color of his eyes, according to the religious taboo of the tribe, he will commit suicide in the tribal square at noon the next day in front of everyone, and the tribesmen are absolutely religious, and they will follow this taboo.

The people of this tribe have good eyesight, they can see the color of everyone else's eyes, that is, they know the color of everyone else's eyes. The people of this tribe do not use mirrors and do not look at their eyes from the water, in short, they cannot know the color of their eyes from the outside world. Perhaps it was this religious taboo that made the people of this tribe not use mirrors.

The people of this tribe all have a high degree of logical reasoning. They also knew that the other members of the tribe had a high degree of logical reasoning, that the other members were absolutely religious, and that the other members knew the color of the eyes of everyone other than themselves.

The inhabitants of the island have two colors of eyes, brown and blue, of which 900 have brown eyes and another 100 have blue eyes. But every resident does not know this, because he does not know the color of his eyes. People with blue eyes can see that there are 900 people on the island with brown eyes and 99 people with blue eyes. Brown-eyed people are similar.

One day, an outsider came to visit Wèn on the island. The eyes of the outsiders are blue. One evening, in gratitude to the inhabitants of the island, the outsiders gave a speech to all the inhabitants. Outsiders are unaware of the island's taboo on eye color, and in his speech, he mentions, "How unusual it is to see a blue eye like mine here."

Now the question is, what are the consequences of this statement?

Liu Meng said with a smile: "This question is very interesting, students who study computer science can also try it, this is actually a very esoteric programming topic." It involves the deep problem of interruption and triggering. ”

"What can happen to this? There are no consequences. As soon as Liu Meng finished speaking, some students in the audience said to the classmates next to him in confusion.

The classmate next to him said angrily: "You are a pig's brain, Professor Liu Meng just said that this is a deep-seated problem." That's definitely not as simple as you think, how many of the three questions you just had?"

"Well, it seems that I have to put some thought into it, and maybe I can join Professor Liu Meng's team if I have any experience. ”

"Don't daydream, a god of learning like Han Yan doesn't accept it directly, how can we be a scumbag of water and wood in the eyes of Professor Liu Meng. ”

"Hey. At the beginning, in our city, I was also a god-like storage zài.,Attracted the admiration of many young classmates.,I didn't expect to be a scum storage zài when I arrived in Mizuki.。 I don't even have a girlfriend until now. ”

"Don't say it, if I knew it was like this, it would be better to go to an ordinary school to be our chicken head, this fucking phoenix tail is really suffocating. ”

"I still don't have the ability. Look at Professor Liu Meng, who is just an Bingcheng University of Technology. In the past few years, I have solved a few advanced problems, and I have become a professor and a national reputation, and I have become a judge of our Mizuki University Grand Prize. ”

"Come on, I watched Professor Liu Meng's performance on the Guinness Intelligence Challenge in the United States, which was simply against the sky, and it caused a lot of impulse in the United States at that time. I'm afraid that people are not interested in exams in high school, and they have been working on world-class problems. It's like we are exams, exams, and exams, and we have become a machine that can only take exams and not study. ”

"That's right. ”

……

The students in the audience were talking.

Professor Liu Meng said: "Okay, Han Yan, go down, hurry up and study, don't bring your thinking into a dead end." ”

Han Yan had already started to check the calculations with a blank look, and began to write and draw with a notebook and pen with him, and when he heard Professor Liu Meng speak, he nodded and retreated, as if he didn't care about the result of the special prize, in his opinion, being able to join Professor Liu Meng's team was much more important than winning the special prize.

The 10th was Liu Junyan from the School of Architecture, and finally a bunch of boys came over and began to come to girls.

He has won the first prize in the professional foundation competition of the "Artificial Environment Discipline Award of Colleges and Universities".

He has won the first prize of the first National College Student Energy Conservation and Emission Reduction Social Practice and Technology Competition.

Students of the 5th phase of the "Siyuan Plan".

The credit score of the university has ranked first in the department for six consecutive semesters in three years, and the credit score of the basic course of mathematics and science has reached 95.4 points. ”

Liu Junyan said in her defense: "In social work, we should promote ourselves and others and serve the society, and in scientific research, we will come from life and go to life. In the summer practice of my freshman year, I felt the interference brought by the arid and hot climate in Northwest China to people's life and work, and after continuous study, I developed an air conditioner suitable for the arid areas of Northwest China, so that people can afford to buy and use it. I hope to do scientific research that truly solves the problems of people's livelihood, and cares about the warmth and well-being of the world. ”

Hou Zhengang was half angry with Liu Meng, then smiled and said softly: "This classmate, don't be arrogant, your grades are good enough, different majors are not good to compare together, you can develop an air conditioner for arid areas in a down-to-earth manner, and solve the problem of the national economy and people's livelihood, which is really remarkable." ”

Liu Junyan nodded and smiled: "Thank you, Professor Hou Zhen, for your recognition." After speaking, she looked straight at Professor Liu Meng, and it seemed that she still cared about the comments of Professor Liu Meng, who was in the limelight, and the girl was still very confident in her heart.

"Good, let's be next. Professor Liu Meng only said one sentence, and Liu Junyan's eyes were obviously disappointed.

The 11th person on the stage was Xu Man, a student from the Department of Precision Instruments, whose declaration was: to be a homework girl with temperature.

She has served as the secretary of the organization group of the Youth League Committee of the Department of Precision Instruments, a member of the 2nd Council of "Spark", a member of the 4th project team of "Siyuan", and a member of the study committee and branch secretary of the 14th class of Jing.

Her three-year results ranked first in the department.

She is also a member of the Mizuki-Berkeley Global Technology Entrepreneurship (GTE) Program, and was selected as a team member to participate in the UC Berkeley and Silicon Valley exchange tour in May 2007.

Her paper "ALong-termStablePowerSupplyμDMFCStackforWirelessSensorNodeApplications" was included in J.Micromech.Microeng.

Xu Man said in his defense: "After three years of growth, the self-deprecating word 'engineering girl' in my freshman year has become my warmest label of belonging and self-confidence. When I was volunteering, I found that many people were disabled because of diseases that could not be detected in time. We don't just need high-end equipment. There is also a need for instruments that are close to people's livelihood. In order to refresh the Fail in the real yàn book, I continued to experiment in the real yàn room 24 hours before returning to China. We always have to accept continuous failure in order to keep our original dream. ”

"If you fail in the selection of the grand prize this time, what will you do first?" Professor Liu Meng immediately asked.

Xu Man was very happy to get Professor Liu Meng's question. Tilting his head and thinking for a while, he said: "I should be quite unhappy, after all, no one can be indifferent in the face of failure, being able to bear failure does not mean that you will not be sad if you fail, and then you may have a meal with two or three friends, and then sing and sing." ”

"Well, it's not easy for a good person to face failure, you seem to be interested in entrepreneurship, which one do you prefer in technology and business?" Professor Liu Meng then asked.

Xu Man was a little embarrassed and said, "Maybe it's because I'm a more practical engineering major." I am not very interested in technologies that have no application prospects, and I can't compare with Professor Liu Meng, who studies the limits of human intelligence. ”

That's a very clever answer. And the girl also wittily used praise to counter Professor Liu Meng's army, Liu Meng couldn't hear it, and smiled disapprovingly: "That's very good, in fact, I also have this idea." The reason why I have devoted several years to studying the problem of mathematical conjecture. A large part of the reason is that my enlightenment teacher, Mr. Kong Jidao, has a great influence on me, but I only found great practical application after theoretical research, I want to say to you that it is very good to be a practical person, and it is better to be practical in scientific research, but what. Sometimes making something seemingly useless can be a treasure trove. ”

After a pause, he said, "It's like two salesmen going to an island where they don't wear shoes to sell shoes, and one of them thinks that the people on the island don't wear shoes. Definitely can't sell, there is no market at all, and the other salesman thinks that this is a huge market, because everyone is not wearing shoes, if you spend a lot of energy to change everyone's habits, then immediately everyone needs a pair of shoes, hehe, which one do you say is more clever? Sometimes the dividing line between truth and falsehood is very unclear. ”

Xu Man listened to Professor Liu Meng's analysis thoughtfully, and then a smile appeared on his face, Professor Liu Meng told him that the research has reached a certain level, and it is difficult to distinguish whether there is a practical application before the research, so whether to go to the research or not? Xu Man nodded and said sincerely: "I am taught, Professor Liu Meng is worthy of being an international master, I don't know if I can join your team?"

Professor Liu Meng simply said, "I'm sorry, my team doesn't need you like this." ”

A trace of sadness flashed on Xu Man's face when he heard this, only to hear Professor Liu Meng say again: "This is also a failure for you, so I would like to know what you will do if you dare to face failure?"

Xu Man said with a happy expression on his face: "I am going to wait for the end of the review meeting and follow Professor Liu Meng all the time, I will follow you wherever you go, in fact, I didn't introduce another trait of mine just now, that is, persistence like a fool." A smile appeared in the corner of his eye.

Liu Meng smiled: "This may not have any effect on me, I was once pestered by a girl like this, but it is useless." ”

Xu Man suddenly said very boldly: "Then I will pursue Professor Liu Meng, for an engineering girl who only looks at practicality, there is nothing more effective than this, as the saying goes, women chase men." ”

Liu Meng almost fainted, and said with a haha: "Okay, you can join my team, but it just happens to be a little sister who boils water and makes tea, you should be competent." ”

Xu Man smiled very slyly and nodded: "I am proficient in the tea ceremony, Professor Liu Meng, and I once developed a smart tea making machine at home, with a high content of tea polyphenols." (To be continued......)