Dai Binbin's chapter push is really effective.

Just overnight, Su Mu found that his collection had tripled, to 1500!

It was also at this time that Su Mu was shocked to find that Dai Binbin was probably not as simple as lv5.

Through the traces of readers, Su Mu found Dai Binbin, which was actually one of the books that went to the young channel to dominate the list!!

In the writer's forum, it was even said that he had touched the threshold of the Great God Covenant.

Who would have thought that the author of this quasi-great god covenant was actually just a high school student??

Su Mu's evaluation of Dai Binbin was a little higher in his heart.

Doubled the collection.

I'm in a good mood.

Add a new chapter!

Following.

The second test officially began.

The mood fell to the bottom in an instant.

Although the coach had already anticipated it after the first test, the second test could be very difficult.

However, it still far exceeded the candidates' expectations.

For the first question, the length of the question is a full sheet of paper.

It is a computational problem, with a variation of Poincaré's conjecture.

Su Mu retracted the sentence that the shorter the question, the more difficult it became.

He felt that it was difficult to apply any experience to math problems now.

Poincaré guessed that Su Mu knew that the seven grand prize problems of the millennium were the only ones that had been proven in the past twenty years.

Although simplifications and variants have been carried out.

But let a group of high school students solve this kind of problem.

Is it really something that people do?

Ge Jun enhanced version of the appendage??

Question 2.

There are 2019 users on a social network, and some users are friends with each other, as long as user A is a friend of user B, then user B is also a friend of user A, and the following operations can be performed repeatedly, with only one operation performed at each moment:

If the three users A, B and C meet that A and B, and C are all friends, but B and C are not friends, then the friendship relationship between them will be changed at the same time, that is, B and C will become friends, but A and B will no longer be friends, A and C will no longer be friends, and all other friends will not change

It is known that there were 1010 users with 1009 friends each and 1009 users with 1010 friends each.

Prove that there is a sequence of actions such that at the end of the operation, each user has at most one friend.

When I saw Su Mu's question.

He only had one lyric in his head.

"Friends walk together for life"

"Those Days Are No More"

However, using a friend to come up with a question is too perverted, right??

Really when a friend is sent by the state??

The third question is even more confusing.

It's also a custom question.

Coins issued by the Bank of Bath were struck with an h on one side and a t on the other, and Harry had n of these coins and lined them up from left to right, and he repeatedly did the following: if there was exactly a k(&a;a; ap; gt; 0) if the h side of the coin is face up, he will flip the k-th coin from left to right; If all coins are T-side up, the operation is stopped, for example: when n = 3, and the initial state is tht, the operation process is tht→hht→htt→ttt, a total of three operations are performed and then stopped

(a) Proof that for each initial state, Harry always stops after a finite number of operations,

(b) For each initial state C, l(c) is the number of operations Harry took from initial state C to when he stopped operating, for example

l(tht) = 3 l(ttt) = 0 Finding c is the average of l(c) obtained when all 2n possible initial states are taken

If you say that the difficulty of trying it yesterday is one.

Then, the difficulty of today's second test has soared to ten!!

The students in the examination room also fell into an extremely embarrassing state, and even ten minutes after the exam started, there were only more than ten students in the huge examination room to write!!

Su Mu frowned tightly, and decided to do it backwards from the third question, from the intuitive situation, the difficulty of the first, second and third questions should be decreasing.

It's just that with Su Mu's level of the eighth level, it has been proved for more than 40 minutes, and he has only completed the first question of the third question!!

Although he is confident that he can deduce it step by step through algebraic methods, the time to complete this competition is probably not enough!

"It's scary, isn't it? I'm in grade 8 math, and I can't finish the problem?? ”

Su Mu's heart was full of 10,000 heads.

You must know that in the national competition of re-creation, he won the first place steadily by relying on seventh-level creatures.

But in the math national competition.

Grade 8 math is a bit insufficient?!

It is no wonder that the annual Olympiad funds in eastern Zhejiang Province are so much higher than that of biology, and because of the difficulty, mathematics will lose half more hair than biology!!

"Ding, you used a green skill point, reached math level 9, and the current score is 0/100e"

After hesitating, Su Mu directly upgraded his math skills to level nine!!

Fortunately, so many competitions have accumulated a lot of skill points during this time, otherwise it would be really insufficient!

"Bang!"

One student's stool fell to the floor, startling the students in the classroom.

The invigilator hurriedly stepped forward to check.

I saw that the student's face was pale and his hands were a little trembling.

"Are you alright??" The invigilator's tone was very worried, and then he turned to look at the other teacher, "Go and inform the medical team first, so as not to cause any problems." ”

The candidate shook his head repeatedly, forced himself back to his seat, and picked up the pen again.

Su Mu smacked his tongue slightly, no wonder he saw an ambulance when he entered the school yesterday, it was actually prepared for this situation??

If you take an exam now, your life will be in danger??!

It's too hard, isn't it?

With a sigh, the classroom fell silent again.

After ascending to the ninth level, Su Mu still felt a lot of difficulty.

But the train of thought finally cleared up.

With a sigh, Su Mu continued his answer with great solemnity.

"Assuming K coins H face up, then from left to right"

"When n=1"

"When remembering n coins, the average value in the inscription is an, and the corresponding average value is bn, and the recursive formula is"

It's not done

I didn't finish it

When the bell rang for class, Su Mu felt extremely sad in his heart.

Originally, it was planned that it would be enough to upgrade to level 8 in mathematics, but now, not only did it take one more skill point, but it didn't even finish the test paper, which was too uncomfortable.

In the last half an hour, Su Mu had already found some ideas through the Königsberg Seven Bridges problem and Euler's demonstrative number theory, but still did not come to a final conclusion.

The title of this question is too complicated, and Su Mu even thinks that getting io may also be the final finale.

Under the urging of the invigilator, Su Mu reluctantly left the examination room, he had not experienced this feeling of not finishing the test paper for a long, long time.

"Su Mu."

"How's the test? Have faith? ”

As soon as he got out of the examination room, Su Mu ushered in Sun Bo's death question.

。