Library.

Yang Yiyi is still consulting the relevant literature on the topic of hard work.

According to Yang Yiyi's own words, their project is speeding up and is ready to be completed within this month.

Chen Zhou, who was beside Yang Yiyi, was burying his head and studying the question of hail conjecture.

After formulating the hail conjecture problem, Chen Zhou is conducting related paradigm research.

[X1=1, substitute the formula: X2=(3×1+1)/2^2=1, end.] 】

[X1=3, substitute formula: X2=(3×3+1)/2=5;X3=(3×5+1)/2^4=1, end.] 】

【......】

Chen Zhou hopes to find some patterns through substituted examples.

But it was obviously a lot harder than he thought.

Chen Zhou looked at what he had written, his brows furrowed slightly, and he thought to himself: "After the iteration of Xn+1=(3Xn+1)/2^m, until the formula of (3Xn+1)/2^m=1 is established, there must be two conclusions......"

While thinking, Chen Zhou wrote on scratch paper:

[1. After any Xi enters an iteration, it will not return to Xi, that is, there will be no digital loop. If a cycle occurs, this is a counter-example, which means that the hail conjecture has been falsified. 】

[2. After Xi enters the iteration, the value will not diverge, that is, the value will not become larger and larger until infinity, but will be replaced within a limited range. 】

Chen Zhou looked at the two conclusions he had written, and he didn't feel much joy, but was worried about how to prove them.

I have to say that through the research of the past few days, he discovered a fact.

That's this thing, it's really difficult, it's harder than asking him to solve a thousand super-outline questions from Wu Xiping......

Of course, this is just Chen Zhou's complaint in his heart.

Compared with solving a thousand super-outline problems from Wu Xiping, he is still more willing to spend his time on the research of the hail conjecture.

Chen Zhou remembered that the hail conjecture had been verified to a natural number of 5×2^60 in 2009, and there was no counterexample.

In this case, the hail conjecture is most likely correct.

Thinking of this, Chen Zhou opened the wrong question set and read it seriously.

The mistakes are the wrong directions that have accumulated in the past few days.

Sometimes, mistakes are the guiding light.

The key is whether you can reflect on your mistakes and find the right path.

After Chen Zhou read it seriously, he began to try another method.

Although this method was considered unlikely to work from the beginning.

But it's always right to try.

Stagnation is even more terrifying.

Taking out a piece of scratch paper again, Chen Zhou began to write after replacing it with a new refill:

[Starting from n=1 and substituting Xn+1=(3Xn+1)/2^m, you can get X2=(3X1+1)/2^m.] 】

[If X2=1, then X1=5,21, 85, 341,1365, 5461, 21845,.....]

[In the same way, when n=2, you can get X3=(3X2+1)/2^m2, and then substitute X2=(3X1+1)/2^m1, that is, X3=[3×(3X1+1)/2^m1+1]/2^m2=(9X1+3+2^m1)/2^(m1+m2). 】

[Again, let X3=1, then X1=3, 13, 53, 113, 227, 909,.....]

[The above value is the result of inverting the equation of X3 and using X1=[((2^(m2-1))/3×2^m1)-1]/3. 】

[In the same way, use the equations of X4, X5, etc., which are constantly substituted, to carry out reverse deduction ......]

Chen Zhou started from X2 in this way, and the pen in his hand continued to write until the equation of Xn was written, and then pushed back.

didn't rush to write out the reverse thrust of X1, Chen Zhou shook his head slightly.

The previous X2, X3, and X4 are all easy to prove.

But in this direction, when n is extended to any number.

Instead, an inverted problem occurs.

Because using Xn's formula, if X1 is pushed backwards, X1 will have problems.

It's a big problem.

As the initial value of X1, the 2^(m1-1) inside it contains the future value part 2^(m(n-1)-1).

It is an unprovable issue.

Chen Zhou also stopped his pen, habitually lit it on the scratch paper, and did not continue to write.

The final result of these calculations told Chen Zhou that he was back to the original point of the problem.

I flipped through the wrong problem set, and all the equations just now appeared on the wrong problem set again.

Yes, this unlikely road was blocked again.

Putting down the pen, Chen Zhou subconsciously wanted to scratch his head, but immediately stopped this action.

Compared to holding a pen, constantly pointing scratch paper, and scratching your head when you encounter problems, it is not a good habit.

In case, it becomes the same as Zhang Zhongyuan, then it will really respond to his sentence, which is very similar to when he was young......

Beside him, Yang Yiyi noticed Chen Zhou's movements and glanced at the dense calculations on the scratch paper.

She asked in a low voice, "Do you want to go out and get some air?"

Chen Zhou turned his head to look at Yang Yiyi and smiled slightly: "Not for the time being." ”

After speaking, Chen Zhou picked up the pen again and continued to attack the hail conjecture.

Time passed quietly at the tip of the pen.

Two weeks have passed since the Qiusai.

April 5th.

Ching ming festival.

As if to meet the occasion, it has been raining lightly since the morning.

Chen Zhou and Yang Yi had no choice but to cancel their morning jog plan.

However, the two did not snooze, but got up directly to have breakfast.

While eating breakfast in the cafeteria, Chen Zhou received a phone call.

It was the leader of the Qiusai who called.

He first congratulated Chen Zhou on successfully being shortlisted for the finals of five subjects, and then explained some precautions for the finals.

Hanging up the phone, Chen Zhou realized that half a month had passed.

And in 1972, Professor Conway of the Institute for Advanced Study at Princeton University proved that the natural generalization of the problem is the algorithmically undecidable hail conjecture.

In 1990, two professors from the Harvard Institute of Mathematics and the Center for Advanced Study at Stanford University proved that the hail conjecture was in fact indeterminable in arithmetic grades.

In 2011, Tao Zhexuan called the hail conjecture unlikely to be proven by current technology.

Chen Zhou is the same, it can almost be said that there is no progress.

But there are still gains.

In the process of research, Chen Zhou at least figured out how difficult this problem is.

It's no wonder that the great mathematician Ethi said that mathematics is not mature enough to solve such a problem.

In addition to this, Chen Zhou also got some additional gains.

He became more proficient in the use of mathematical tools.

Retracting his thoughts, Chen Zhou looked at Yang Yiyi, who also received a call.

When Yang Yiyi hung up the phone, Chen Zhou asked, "Qiu Sai's team leader?"

Yang Yiyi nodded lightly: "Well, the two subjects I chose were shortlisted." ”

Chen Zhou was not surprised by this result, if Yang Yiyi was not shortlisted, he would be surprised.

Back in the dormitory, Chen Zhou saw that Zhao Qiqi and the three of them had already gotten up and were sitting at their desks, checking the results of Qiu Sai's competition.

It seems that these three guys also received a call.

Chen Zhou handed them breakfast, sat down at his desk and began to sort out his scratch paper.

Zhao Qiqi asked while eating steamed buns, "Brother Chen, don't you check the results of Chaqiu Race?"

Chen Zhou's hands kept moving, and he replied: "All five subjects have been shortlisted." ”

Zhao Qiqi took another bite of the bun, and his voice was a little vague: "No, I mean the specific results." ”

Zhu Mingli also said: "Yes, Chen Zhou, you must be shortlisted." But don't you even look at the specific results?"

Chen Zhou replied: "Just know that you are shortlisted, as for the results, they should be good, and it is the same whether you check it or not." ”

Hearing this, Zhao Qiqi and Zhu Mingli stopped talking.

Li Li glanced at Chen Zhou and silently closed the open webpage.

Until the three of them finished breakfast, Chen Zhou never touched the computer.

Zhao Qiqi glanced at Chen Zhou again, and then silently entered Chen Zhou's information into the official website and checked it.

Zhu Mingli was keenly aware of Zhao Qiqi's movements, and he quietly moved his body and approached Zhao Qiqi.

Although Li Li did not move, he also stared at Zhao Qiqi's computer screen.

As the page was refreshed, the three of them saw Chen Zhou's written test results.

Zhao Qiqi couldn't help but snort: "!

Zhu Mingli followed: "Awesome!"

Li Li retracted his gaze, and just said with emotion: "I didn't expect that such a difficult number theory paper can get full marks in all subjects......"

Hearing the words of the three of them, Chen Zhou still didn't stop the movements of his hands, but just asked lightly: "Which of you has a full score in all subjects?"

Chen Zhou thought it was one of the three Zhao Qiqi who had achieved a perfect score in all subjects.

These three people, in Chen Zhou's opinion, only Li Li has this possibility.

Li Li replied: "It's not me, I can't, it's you ......"

Hearing this, Chen Zhou was slightly stunned, turned his head slightly, glanced at the three of them, and then noticed the content on Zhao Qiqi's computer.

He didn't expect Zhao Qiqi to actually check his grades.

"Uh...... Brother Chen......"

As soon as Zhao Qiqi was about to explain, Chen Zhou said: "It's okay, just check." ”

Before Zhao Qiqi could breathe a sigh of relief, he heard Chen Zhou say again: "It's the same as I thought, the results are good." ”

Zhao Qiqi couldn't help but say: "Where is this good, this score must be like what Li Li said, it is the only full score in all subjects!"

Zhu Mingli and Li Li dragged Zhao Qiqi at the same time.

Zhu Mingli said: "Have you forgotten what it means to be good?"

Zhao Qiqi was speechless for a moment, and he thought of Chen Zhou's sentence "I did well in the test......

Chen Zhou smiled slightly and continued to sort out his scratch paper.

In fact, he was not surprised by this result at all.

Not to mention, he already knew the perfect score for all subjects through the wrong question set.

Even if he didn't read the wrong question set, Chen Zhou was basically sure that he had a perfect score in all subjects.

For him, who has finished his undergraduate course, it is not right to participate in the mathematics competition for college students across the country and get a full score.

What should have been done, the final result is just a matter of course.

Therefore, after seeing his results from Zhao Qiqi's computer, Chen Zhou's heart did not fluctuate.

Of course, if he wins the gold medal in the finals and the team gold medal and wins all the first places in one fell swoop, Chen Zhou will still be very happy.

After all, the meaning is different, this is the first math competition in which he participated.

Compared with Chen Zhou's indifference, with the hot results of the written test of Qiu Sai, students from all regions of China who participated in Qiu Sai began to check the written test results of Qiu Sai on the official website.

For a while, this not-so-powerful official website was at risk of collapsing.

Thanks to the timely arrangement of personnel for maintenance by the event officials, it was able to withstand the climax of this wave of result inquiries.

At the same time, the official announcement of the finalists and praise list of this competition has also spread.

To be shortlisted is to advance to the finals.

As for praise, it is natural to praise the players who played well in this competition.

You didn't make it to the finals, but you guys were excellent.

On the campus of Yan University, this list was also screenshotted and posted.

In order to echo the previous voting post of the Qiusai gold medalist, the post of this shortlist was named by the poster [Qiusai Voting 2.0, may I ask the person you voted for, is he still there?]

When Chen Zhou first saw this post, he also liked it.

This poster has a good job of naming it.

This is a good time, and it is also very slippery.

This kind of title is easy to attract visitors.

It's like Chen Zhou, don't you just like it?

In the post, it is the analysis of various gods.

Chen Zhou simply swept it.

It wasn't until one person listed all the names of the five members of their team that Chen Zhou took a closer look.

[The strongest team in this Qiu Competition!All five people were shortlisted for the finals!]

[Chen Zhou, Yang Yiyi, Li Li, Zhu Mingli, Zhao Qiqi, this is a combination of the peerless double pride plus the three, and Li Li, Zhu Mingli, and Zhao Qiqi are all Chen Zhou's roommates who are one of the peerless double pride!]

[Is it really one person who affects the entire dormitory? I boldly assert that this team will win the gold and silver awards of this Qiu Competition!]

"Does one person affect the entire dormitory?" Chen Zhou smiled slightly.

Indeed, he had a certain influence on the three people in the dormitory.

From the fact that Zhao Qiqi and Zhu Mingli have never played masturbation again, it can be seen that this has a far-reaching impact.

Seeing Chen Zhou's smile, Yang Yiyi asked curiously, "What are you looking at, and you are still laughing while watching?"

Chen Zhou handed the phone to Yang Yiyi: "Have you read this post?"

Yang Yiyi took it, glanced at it, returned the phone to Chen Zhou, and said helplessly: "Yurou and Li Jing have already shown it to me, and now the dormitory doesn't discuss giants every day, and starts to discuss who can win the gold medal between the two of us." ”

Hearing this, Chen Zhou smiled again: "It's all the same anyway." ”

What Chen Zhou didn't know was that on Weibo, the Department of Mathematics of Yan University @ him.

There is only one sentence to say, waiting for him to lead this team and win all the gold medals!

It was followed by the official blog of the Department of Physics of Yan University, which reposted and liked this Weibo.

With the news of the official blog, netizens who have been paying attention to Chen Zhou on Weibo only then knew that Chen Zhou actually went to participate in Qiu Sai again.

For a while, Chen Zhou's comment area was bombarded again.

And the voting posts that were originally lively on the campus of Yan University have also been moved to Weibo.

Of course, this voting post is only the list of shortlisted personnel.

But like the campus network of Yan University, Chen Zhou's name quickly reached the top and was far ahead with an absolute vote difference.

Then, to everyone's surprise, Qiu Sai's official Weibo quietly liked this Weibo of the Department of Mathematics of Yan University.

This operation directly triggered group complaints from netizens.

However, no one doubts the fairness of the competition.

After all, behind Qiu Sai is Yan Da's old rival.

Moreover, after accepting everyone's complaints, Qiu Sai's official blog posted Chen Zhou's full score in all subjects, and attached Mr. Qiu's comments: "The calculation is extremely rigorous, the logic is meticulous, and the thinking is extremely clear." ”

As soon as this Weibo was released, it was more powerful than everyone's words.

And below this Weibo, in addition to a large number of comments from netizens.

The official blogs of major colleges and universities have also collectively gathered the excitement.

The two old rivals of Yan Da Shui Mu are also surprisingly consistent.

And with more and more people paying attention, Qiu Sai, a college student mathematics competition that has only been established for a few years, has become more widely known.

This is also extremely beneficial to the development of an event.

As the object of discussion, Chen Zhou never paid attention to this matter after he withdrew from the campus network.

He is still plain and Yang Yiyi, according to their plan, spending every day in fulfillment.

After the results of the Qiu Sai written test were announced, another week later, Chen Zhou received an email.