Chapter 136 No, yours is the one
During the pairing process, Xu You also took into account the number of 2 and 5 that appeared.
Undoubtedly, the number of 2s must be greater than the number of 5s.
In this way, the problem becomes to count how many factors of 5 there are in the factorial number.
"Wait a minute...Numbers like 25 and 125 actually have more than one factor of 5 in them."
Xu You quickly noticed this important issue.
If this is ignored, the final result will be wrong.
Finally, Xu You edited a short five-line code on the computer and sent it to Peng Jun.
“Not bad!”
After seeing the code sent by Xu You, Peng Jun couldn't help but express his affirmation of Xu You's answer.
Although this question is not a difficult one.
But he was able to give such a beautiful answer in just a few minutes.
Peng Jun knows that most undergraduate students majoring in computer science may not be able to do this.
"This child should have made it himself."
Peng Jun believed that since Xu You asked him the questions, he would definitely not search for the answers.
But in order to further determine Xu You's ability, Peng Jun decided to give Xu You another difficult question, the kind that could not be found on the Internet.
"Well done, the code is very concise. I'll give you a more difficult problem."
This time, Peng Jun sent a question that he had adapted to Xu You.
Looking at this new question, Xu You quickly fell into deep thought.
"Given k ordered arrays: L1, L2, ..., Lk, each of length n, the arrays can be preprocessed in linear time. Then answer the following query: given x, answer what is the first element in each array that is less than x?"
This time, Xu You indeed felt the increase in difficulty of the questions.
If Xu You hadn't finished these courses these days, he probably wouldn't even be able to understand the questions.
The first method Xu You thought of was to perform a binary search on each array.
But in this case, the complexity will be very high, reaching O(klogn).
Soon, Xu You found another idea.
"If we use Fractional-Cascading, we can reduce the complexity to O(k+logn)."
The so-called Fractional-Cascading, also known as the distributed cascading algorithm, can greatly optimize the classic blocking problem.
Following this idea, Xu You re-conceived the algorithm and quickly came up with a new solution.
"In this way, we only need to use binary search for the first time, and then we can just use constant search every time."
After completing the editing of the algorithm data structure, Xu You sent his solution to Peng Jun.
Seeing Xu You's answer, Peng Jun couldn't help but nod repeatedly.
"This kid is really not kidding me. To be able to reach this level, he must have learned all these courses thoroughly."
At this time, Peng Jun also had to praise Xu You's learning ability.
Peng Jun didn't know how Xu You managed to learn almost all the knowledge of the computer undergraduate program in just ten days and mastered it very well.
Even if you spend more than ten hours a day, it is not enough to go through all these courses.
But since Xu You was able to do it, it means he must have his own unique learning method.
"Yes, the answer to this question is also very good. Not only can it solve the problem, but the degree of optimization of the algorithm is also very good. Xu You, you are the fastest learner I have ever seen."
Although this was just a random question given by Peng Jun, it could not fully test Xu You's computer knowledge and ability.
But since Xu You can do so well on any random question, it means that Xu You has probably mastered most of the knowledge.
"I have to thank the teacher for his good teaching! Teacher, do you have any undergraduate thesis topics? I would like to practice with them."
"Okay, I'll send you a few of the last year's undergraduate projects later."
With a computer and questions, Xu You has a lot to do even when he returns to his hometown.
…
Two days before the Chinese New Year, Xu You and Lu Zhiyao prepared to return to their hometown in Shengcheng.
This time, Xu You’s suitcase was finally not filled entirely with books and materials.
Apart from a few particularly important books, the main space in the suitcase is occupied by spare clothes, laptops and other equipment.
Xu You thought, even if he dragged a box of books back home, it would not be enough to read for a few days.
If you want to read a book, just buy it online. It’s not a big deal.
When he saw Lu Zhiyao, Xu You discovered that Lu Zhiyao also had a scarf around her neck.
Lu Zhiyao's scarf is very similar to Xu You's, except for the different background colors, and there is also a cat lying on it.
"Lu Zhiyao, did you knit two scarves at that time?"
"No, I only knitted one at that time, because I had a lot of wool left, so I knitted another one later."
"So, you knitted this one with leftover wool?"
"No, yours is the one." Lu Zhiyao said with a smile.
"But why did you buy so much yarn?"
"I just want to try out a few more colors. Okay, shall we take the subway or a taxi to the station?"
In fact, if Xu You were alone, he would probably choose the subway directly.
Not only is it cheaper, but the subway will be faster.
However, the subway requires transfers, and it is a bit tiring to stand while dragging a suitcase.
"I'll call a car. I've got enough time anyway."
Xu You opened the Qiandu Map app, called a car, and took the initiative to help Lu Zhiyao put her suitcase into the trunk of the car.
After having a meal together at the station, the two boarded the high-speed train on time.
During the journey, Xu You did not study all the time, but talked about something with Lu Zhiyao from time to time.
Lu Zhiyao's grades this semester were also good. Although not as outstanding as Xu You, she also received the college's first-class scholarship.
It is very difficult to get a first-class scholarship at Jida University, which is full of top students.
Lu Zhiyao's ability is not as ordinary as she said.
"Teacher Lu, do you have any insights on philosophical issues recently?"
Last time, Xu You was deeply impressed by what Lu Zhiyao said about the relationship between philosophy and science.
Lu Zhiyao's philosophical thinking is full of rationality, and Xu You also wants to learn more knowledge from Lu Zhiyao.
"It's a philosophical question... By the way, is one of your research areas related to quantum physics?"
"Yes, the first paper I published was about quantum physics."
"Then let's talk about quantum entanglement. In fact, I think quantum entanglement is a very philosophical physical concept."
Xu You is naturally very familiar with the concept of quantum entanglement.
The so-called quantum entanglement means that when two particles interact with each other, their characteristics become a whole property, and it is impossible to describe the properties of each particle individually.
