From all-round academic master to chief scientist

In this way, half an hour before the exam, Lin Xiao was probably the only person in the room who was not thinking about these questions.

In this way, until half past nine, the bell rang for the start of the exam on time. All the candidates present had already thought about the ideas for the first question and immediately started writing on the answer sheet, while those who had no ideas started writing on the answer sheet. Start checking on the scratch paper.

As for Lin Xiao, he stopped thinking at this time, reopened the card with the question written on it, and started reading.

The first question was a geometric proof question. It was not very difficult and provided many conditions. Lin Xiao thought about it for more than a minute and then had a complete proof idea.

Then he started answering on his answer sheet, and after about six minutes passed, he finished.

In other words, he completed the first question in less than eight minutes.

Of course, this is also because there are not many steps. Once the auxiliary lines are ready, Lin Xiao only needs less than seven lines to complete the proof.

"Send points."

Lin Xiao made a brief evaluation, and then looked at the second question. It was still a sub-question, but the process and the words to be written were more than the first question, so he spent a total of fifteen minutes. ’s time before it’s done.

Then, finally came to the third question.

Generally speaking, IMO two-day exams will have two relatively simple questions and a finale question, so this third question is today's finale question.

Lin Xiao took it in his hand and finally nodded. The level of this question is reasonable.

[The inverse Pascal triangle is an equilateral triangle matrix composed of effects, such that except for the bottom row, each number is the absolute value of the difference between the two adjacent numbers below it. I would like to ask, is there an inverse Pascal triangle of row 2018, containing all integers from 1 to 1+2+3+...+2018? 】

After briefly looking at the question stem, I found that this is a combination question, and the question type is more algebra-oriented.

He thought about it briefly, first found out the recurrence equation based on the meaning of the question, and then continued to make changes.

After spending about five minutes, he finally compiled a function.

Looking at this function, Lin Xiao touched his chin, because a wonderful inspiration flashed in his mind.

"Can I convert this function into a trigonometric function and then use... Euler's formula?"

He just did it as he thought. He directly changed the function, and then incorporated Euler's formula into it.

After a few simple steps, a magical scene appeared in front of him.

This brand-new function simplified almost the entire problem for him.

Now, he only needs to slightly change the original recursion formula, and then use the simple drawer principle to get the final result.

[...So we can easily get that there is no anti-Pascal triangle consisting of {1, 2,..., n(n+1)/2} with n=2018 rows.

Certification completed. 】

Lin Xiao wrote the last two words one stroke at a time, and nodded with satisfaction.

"This question is quite interesting."

I blew my paper and saw, well, the third question used a total of eleven lines, which was shorter than the second question.

As for inspections, there is no need to inspect. If the organizing committee says he is wrong, then he will directly question the level of the organizing committee.

However, the level of the organizing committee is obviously still there, so this situation basically does not need to be considered.

"OK, it's time to go back. I don't know if Professor Pompieri has sent me an email."

With this thought in his mind, Lin Xiao raised the red sign next to him that said 'help'. Soon a staff member saw his move and walked towards him.

Lin Xiao picked up the banana presented next to him, peeled it off, and ate it.

"Do you need any help?"

"I want to hand in my paper."

"Okay, do you want to hand in... hand in the paper?"

Suddenly realizing what Lin Xiao said, the staff member was stunned.

Now, it seems like the exam has only started less than fifty minutes ago, right?

Are you going to hand in the paper directly?

Could it be that you gave up?

It's not like there are no people who hand in papers very early, but people like this who turn in papers only fifty minutes after taking the exam are a bit too rare.

Even if the players from poor countries don't receive as much math training as those from countries with strong education, they won't give up in less than an hour, right? How about sitting down for an hour or two to express your attitude?

And seeing that Lin Xiao is from Huaguo, this staff member couldn't believe it even more. Huaguo is one of the top three teams in IMO all year round, and has often won first place in the past. How can their players give up so easily?

Lin Xiao confirmed again: "Yes, I want to hand in the paper. There should be no time limit for handing in the paper, right?"

"Ah... No, no, you can hand in the papers at any time... Well, except for the test papers, answer sheets, and these cards, you can take everything else with you."

"OK."

Lin Xiao nodded, then took the stationery bag, the chocolate bar and water, then stood up, eating a banana, and walked towards the exit.

Obviously, more than 600 other people are still busy writing questions, but here there is a person leaving the examination room, which will definitely attract the attention of others.

The candidates sitting around Lin Xiao couldn't help but glance at Lin Xiao at this time, their hearts filled with disbelief.

This person just handed in the paper?

The contestants who saw Lin Xiao talking to Professor Pompieri last night would naturally not believe that Lin Xiao left the examination room because he really couldn't finish it. Then there was only one possibility left, that he had already finished writing.

These players couldn't help but feel a sense of despair coming from the huge disparity.

Most of them have just started the second question, and a small number of contestants from weak countries are struggling with the first question. In the end, they have even finished the third question?

Is this the guy who can talk cordially with Fields Medal winners and receive invitations to give lectures at the International Congress of Mathematicians?

This kind of strength is simply intimidating to them.

On the other side, all six players from the American team also saw it. Although they didn't hear Lin Xiao say that he wanted to hand in a paper, this meant that Lin Xiao might have gone to the bathroom, but he saw Lin Xiao holding a banana in one hand. While walking and eating, the other hand was holding a stationery bag, which was obviously a sign of handing in papers and leaving.

This made them extremely shocked. Lin Xiao actually only spent an hour... No, strictly speaking, he finished three questions in less than fifty minutes?

Even James Lin, recognized as the most powerful player in the American team, is still a few small steps away from completing the second question and has not yet started writing the third question.

He was completely convinced. Why did he have to fight with such a person? He knew that he was so awesome, but in the end he still had to disbelieve in evil...

He sighed softly, regained his composure, and worked on his own questions calmly.

Here’s another chapter, asking for all sorts of things.