However, judging from his expression, this arrogant academic master was completely convinced of Lu Zhou's mathematical ability.
"Finally, regarding reference books, I recommend that you read some books on mathematical modeling cases, such as "Mathematical Models", "Mathematical Modeling Algorithms and Applications" and "Basic Tutorial on Mathematical Modeling".
②Remember the number of merchants on the k-th ferry as Uk and the number of followers as Vk. Define the two-dimensional vector Dk = (Uk, Vk) as the decision. The allowed decision set is recorded as D, which can be known from the boat capacity: D={(U, V)|1≤U+V≤V, U, V=0, 1, 2}
"There are four main types of commonly used software, Matlab, Mathematica, Lingo and SAS. You don't need to master them all. You just need to master at least one of them. The key is to be able to use software that suits you to solve practical problems." When saying this , Professor Liu Xiangping is looking at Wang Xiaodong.
"...I'll call her and ask her." Wang Xiaodong looked embarrassed and went outside with the phone.
"In the first round, two followers go over and one follower comes back."
Lu Zhou walked forward, picked up the chalk and started writing on the blackboard.
Wang Xiaodong pushed up his glasses, the expression on his face was still indifferent, as if it was a matter of course.
Indeed, there is no difficulty in this question.
"Of course." Professor Liu Xiangping smiled and made a gesture of invitation.
Teacher Liu took a sip of tea and said slowly: "That's right."
"In the second round, two more followers go over and one follower comes back."
"That's right, but my research direction is towards physics, and I rarely publish mathematics papers." Teacher Liu squinted his eyes, glanced at the door of the classroom, and continued with a smile, "You lesbian, you don't seem to be very reliable. ah."
It can be obtained that S={(X, Y)|X=0, Y=0, 1, 2, 3; X=3, Y=0, 1, 2, 3; X=Y=1, 2}
Although he did not have the opportunity to demonstrate his programming skills live, it was a little regretful for him.
As he spoke, he clicked the mouse and turned the PPT to the next page.
"Can I use the blackboard?"
"It's amazing..." Looking at the writing on the blackboard with a blank look on his face, Lin Yuxiang opened his mouth slightly, looked at Lu Zhou coming down from the podium, and asked in a low voice in surprise, "Don't you even need a draft?"
]
In his opinion, this question was indeed not difficult. Although he didn't use his brain to calculate it, he believed that his IQ could solve it with a little time at most.
Lu Zhou put down his phone and replied with a smile: "I am responsible for modeling, Wang Xiaodong is responsible for programming, and Lin Yuxiang is responsible for writing the thesis and defending it."
Wang Xiaodong was as silent as ever and did not speak.
"Modeling is neither a test of the team's programming ability nor a mathematical ability, but the ability to transform actual problems into data language and solve them. You must remember this."
Even without relying on the power of the system, Lu Zhou quickly figured out the answer and replied.
"As for modeling itself, I don't have much advice. There are no shortcuts other than practicing more and broadening your knowledge. As for programming, I can say a few words."
Lu Zhou smiled awkwardly but politely.
"In the sixth round, the last two followers passed and successfully crossed the river!"
Lu Zhou's eyes lit up: "Teacher, are you also engaged in mathematics?"
This problem is indeed somewhat difficult, but the difficulty is not in mathematics, but in how to abstract this problem into a mathematical problem and solve it.
Teacher Liu also smiled and said nothing more on this issue. After a moment of pause, he continued: "As for the configuration of your team, I suggest you make some adjustments. The same person is responsible for the modeling and thesis, and the rest Two people are responsible for programming. The advantage of this is that the person responsible for modeling has a strong overall grasp of the entire topic and the writing ideas are smoother. However, of course there are also disadvantages, that is, your burden will be heavy. The total competition time is only Three days, which means you must start writing the paper immediately after completing the modeling.”
"In the fourth round, two businessmen go over and a follower comes back."
The expression on Wang Xiaodong's face was unmoved, looking like a master from this world.
Wang Xiaodong pushed up his glasses, nodded and said: "I have used Matlab and SAS before, and there is no big problem."
The teacher was not in a hurry, unscrewed the thermos cup, took a sip of hot water, walked slowly to Lu Zhou's side, and asked with a smile: "What is the configuration of your team?"
Lu Zhou thought thoughtfully: "...are two people responsible for programming?"
Professor Liu nodded: "Knowing these two softwares is basically enough. You need to learn these things by yourself. What I can do is provide guidance when you don't understand."
"I also have some internal school handouts and materials here. You can copy them back and read them, but remember they are not allowed to be shared externally, let alone uploaded to the Internet. Understand?"
"Modeling, programming, writing, standard configuration," Teacher Liu smiled and continued, "Speaking of which, you are the Lu Zhou from the first and third classes. I read your paper and it is indeed a good one. Article."
[①Remember the number of merchants on this bank before crossing the river for the kth time as Xk. The number of followers is Yk, k=1, 2... Xk, Yk=0, 1, 2, 3. Define the two-dimensional vector Sk = (Xk, Yk) as the state, and the state set under safe river crossing conditions is the allowed state set, denoted as S.
"Sorry, I got up a little late. I'm really, really sorry!" Lin Yuxiang walked into the classroom with Wang Xiaodong, looking apologetic and bowing his head to the teacher to admit his mistake.
"Absolutely correct." Teacher Liu smiled and continued, "Even without any mathematical knowledge, this problem can be solved simply through logical analysis. But what if the problem is extended to N businessmen?"
"Before starting the lecture, I hope you will take a look at an example problem first. This problem itself is not difficult, but it can be used as a case of mathematical modeling. I hope that through this set of cases, you can first understand what mathematical modeling is. What?"
After looking at the process on the blackboard, Professor Liu Xiangping smiled and nodded: "Absolutely correct! But from the perspective of mathematical modeling, this work can only be considered half completed. After completing the modeling, we still A program is needed to implement this model. Of course, this model is very simple. I believe that with our student Wang’s ability, a program of this level must be at your fingertips, so I won’t waste precious time here.”
Professor Liu smiled and said: "Okay, that's it for today. I don't have anything else to say. It's mainly up to you. If you need information, come to me and download it. After downloading, go back and review English. .”
Lu Zhou thought seriously for a while and already had a general idea in his mind.
At this time, the sound of trotting footsteps came from outside the corridor, and the last teammate finally arrived belatedly.
Because this sentence is mainly meant for him.
"It's settled in my heart." Lu Zhou said with a smile.
"It's okay. Now that everyone is here, let's start quickly." Teacher Liu Xiangping smiled casually and did not blame her for being late. He turned around and walked to the podium, inserted the USB flash drive into the computer, and He turned on the projector and showed his PPT.
"In the third round, two merchants go over and a follower and a merchant come back."
Looking at the two people in the classroom, Professor Liu Xiangping was stunned for a moment, then asked with a smile: "Are there only two people? I heard there is another one."
"Three businessmen each took a follower to cross the river by boat. A small boat can accommodate two people. The followers secretly agreed that if there were more followers than the merchants on either bank of the river, they would kill people and steal goods. But how to cross the river by boat? The power of the river is in the hands of the merchants. Ask: How can the merchants cross the river safely?"
Lu Zhou smiled and did not give an immediate answer: "I'll think about it again. After all, I have to discuss this matter with my teammates."
"Understood!" The three people said in unison.
"So the key is what are the actual problems your team is facing?"
After a pause, Teacher Liu continued, "Data modeling is actually a process of simplifying an actual problem into a problem that can be expressed using data and a very brief language, and then using mathematical tools to solve the problem."
"Bah, bang, bang!" Lin Yuxiang clapped her little hands and clapped softly, her face full of admiration.
③Based on the above conclusions, the change rule of state Sk with Dk is: S(k+1)=Sk+(-1)^k*Dk
"In the fifth round, two followers go over and one follower comes back."