Xueba's Sea of ​​Stars

Chapter 195 I Have an Awesome Roommate
"So you want us to help you improve your plagiarism detection tools?"

"Well, it's a great achievement to get it done. I guarantee you a scholarship... Well, you don't need a scholarship. I'll treat you to dinner when I return to Shanghai. How about the top floor of Jinmao?"

"Wow, is it so luxurious?"

"Yeah, this is a big project, how about it, do me a favor?"

"Okay, I'll give it a try, but let me tell you first, I'm not as good at programming language as you think."

"It's because you are much better than you imagined." Li Yan shook his head. Although Wu Bin didn't help him solve any actual coding problems, Li Yan was too relieved of his academic ability, but as long as this big guy puts his heart into it The things that have been studied can reach the realm that ordinary people cannot understand.

Both of them belonged to the vigorous and resolute character, so after dinner, Wu Bin and Lin Ziqi followed Li Yan to the student union office.

[Shoulder the mission of the times, gather the power of youth! 】

As soon as you enter the door, there are various party newspapers and promotional posters all over the wall, which can be said to be quite popular, making people feel a sense of mission at a glance.

Under the leadership of Li Yan, Wu Bin met Tang Chengwen, the vice chairman of the Disciplinary Inspection Department.

When he learned that Wu Bin was here to help solve the problem, Tang Chengwen immediately expressed his warm welcome.

Last semester, Wu Bin learned from Li Yan that the student union of USTC does not have the legendary "bureaucratic atmosphere". Everyone regards the student union as a place to exercise their abilities, so the atmosphere is very good.

Although Wu Bin has also heard that some students will play an official role after joining the student union, and even do some private affairs after gaining power, but it is really hard for him to imagine what kind of situation it will be like.

After a few words of politeness, Tang Chengwen described the phenomenon and scope of cheating to Wu Bin.

Wu Bin nodded after listening.

In short, he doesn't need to study how plagiarism occurs, he just needs to develop a better automatic program to effectively find out the plagiarized code from a bunch of submitted homework.

'interesting'

This reminded Wu Bin of a small game he encountered on a forum. The content is to give you two C codes, and you rate the similarity between them, which is an effective training for language understanding.

"let me try."

Wu Bin, a master of the code world, has seen a lot in various forums, but now he is in the University of Science and Technology, and he really doesn't know what kind of old black mountain demon he will meet.

"So smart..."

After brushing several sets of codes, the corners of Wu Bin's mouth turned up. The person who wrote the codes obviously knew that someone would check the similarity of the codes, so he deliberately changed the codes to be complicated.

In addition, there are many students who directly copied the code. It is estimated that they are all hugging their thighs. It can be said that they are completely free. Although this is human nature, it is definitely not a good behavior.

'However, the design of this experiment is indeed a bit boring. It is estimated that most students are not interested in doing it seriously. '

But what is wrong is wrong, and developing this habit is certainly not good for your studies.

"How is it? Is it difficult?" Tang Chengwen, who was standing behind him, asked.

"It's okay, just give me some time."

"That would be great." Tang Chengwen asked Li Yan in a low voice after speaking, "Do you still know friends from Xinyuan?"

"Oh no, he's my classmate from the Institute of Physics."

"Is the Wuyuan so omnipotent now!?" Tang Chengwen was surprised.

"No, he's the only one. He has a wide range of interests and hobbies."

"excellent……"

During the chat between the two, Wu Bin was analyzing the problem. In essence, the problem of checking the copied code was actually given two codes P1 and P2.

The "distance" between d(P1, P2) is required, the smaller the distance, the greater the suspicion of plagiarism.

The premise of solving the problem is naturally to find the problem. After looking at so many codes, Wu Bin almost made a summary in his heart.

The most commonly used method is to modify irrelevant information such as comments, variable names, and capitalization.Then there is code rearrangement, style modification, etc. For example, use the indent tool to filter the code. You must know that everyone has their own programming style. After such a change, it will look very different to the naked eye.

The other two are more technical. One is to add or delete redundant components in the code, such as adding some useless code, or deleting some printed debugging information.

The second is to rewrite equivalent data structures, loops, and local codes, and split and merge functions.

To find out the problem, the first thing Wu Bin needs to do is to optimize the compiler to compile the code. This is very important. Many manually modified equivalent codes can be optimized into the same binary code, and then the instruction sequence of the function can be obtained.

In this way, except for the most technical method of equivalent rewriting of data structures, loops, and partial codes, the other three cheating methods are useless.

Because in the eyes of the compiler, no matter how you indent or adjust, the compiled function will look the same.

Seeing Wu Bin typing codes on the computer, Tang Chengwen and Lin Ziqi both opened their mouths.

Although Lin Ziqi knew that Wu Bin was good at designing programs when she was in the laboratory, she was still shocked when she saw it with her own eyes.

"This proficiency is too high..."

After modeling the similarity of the program into a bipartite graph maximum weight matching problem, Wu Bin turned his head and said to Tang Chengwen: "I want to copy the rest back to the dormitory and work on it. It will probably take a lot of time, is that okay?"

"Of course no problem." Tang Chengwen nodded again and again, "Then I would like to thank you for helping us solve such a big trouble."

Although Tang Chengwen couldn't understand what Wu Bin had done, his calm demeanor made him feel that a person without any skills really couldn't pretend.

"polite."

Wu Bin has been reading physics papers crazily for the past week, and now he stops to do something else, which makes him feel good. He even feels that some new ideas are already being conceived, and with a little more effort, he can come up with them.

After leaving the student union, Lin Ziqi left the team and went to the laboratory first, while Wu Bin and Li Yan returned to the dormitory together.

Turning on the computer, Li Yan turned to Wu Bin and said, "Now I finally understand why so many people like to use "I have a friend, I have a classmate, and I have a colleague to pretend to be B."

Before Wu Bin could speak, Chen Anzhi on the side interjected, "Why, God Wu took you to pretend to be B and took you flying?"

"Yes, I guess it won't be long before the student union will spread the legend that I have an awesome roommate."

"What are you pretending to be? Let's hear it." Chen Anzhi was full of curiosity.

"It hasn't been solved yet, don't listen to his nonsense." Wu Bin walked to Chen Zhian's desk and glanced at the electromagnetic problem he was working on.

"Boss...don't look at me so directly, I'm under a lot of pressure." Chen Zhian said pitifully.

(End of this chapter)