wild 1995

Chapter 9 Graduation Thesis
"Di Ye, are you awake?"

"It's already up, the door is unlocked, just push it."

On the morning of January 1, Feng Shijie came to have breakfast with Di Ye again. After entering the room, he saw him sitting at the desk, writing on a stack of manuscript paper, and asked, "Are you writing a letter?"

"No, the idea of ​​​​writing a graduation thesis."

Feng Shijie walked over to have a look, and said in surprise: "The last semester is almost over, and you haven't started your graduation thesis yet?"

"I have a good relationship with my tutor. He told me to take the postgraduate entrance examination with peace of mind and write my thesis in the next semester. He also rented this room for me to read."

"Your mentor is really nice, what's your name?"

"Liu Shaosong, do you know him?"

"I know this person, but I don't know him. Liu Shaosong is the only returnee Ph.D. in the School of Computer Science. If you hug his thick legs, you will definitely get an excellent graduation thesis."

"That's not necessarily the case, he's very strict."

Last night, Di Ye discovered a new function of the electronic watch, which can be controlled by voice or thoughts to save screenshots of the content on the light curtain to the message box, so that he can plagiarize all kinds of information in 2023 without having to keep talking with Di Ye.

While chatting with Feng Shijie, he copied keywords from the screenshots in the message box. After writing the last few words, he turned off the light curtain, stuffed the manuscript paper into a brown paper bag, got up and said, "Let's go, have breakfast."

Feng Shijie has been a counselor at Yuncheng University for several years. He is a local snake. It only took him a day to find out the details of Di Ye. On the way, he asked: "I heard that you will go to IBM's US headquarters for an internship in March?"

"Not sure yet, maybe."

"You guys who study computer have a bright future. Not only are you easy to find a job, but you can often go abroad."

"Which major did Mr. Feng study?"

"I study materials. If I didn't stay in school to be a teacher, I would have to work as a coolie in a factory."

In 2023, China is already the world's factory, and the four majors of biochemical and environmental materials are still known as the four major tiankengs. In 1995, China's economy had just started, and its GDP was only 10/1 of that of the United States.

After having breakfast in the cafeteria, Di Ye went to the office building shared by the School of Computer Science and the School of Management. On the 5th floor, he found an office with a nameplate of "Liu Shaosong" hanging on the door, and knocked on the door with his fingers.

"Please come in."

The office is also shared. There are two desks. There is a person sitting behind each. One is older, an old man in his 50s, and the other is younger, who looks about 30 years old. According to Di Ye's description, Di Ye walked to the young teacher's desk and said hello, "Mr. Liu, are you looking for me?"

Liu Shaosong attaches great importance to his image. With his delicate parted hair and a pair of rimless glasses, he looks refined. He stares at the computer screen in front of him and asks without raising his head, "Winter vacation is coming soon. Have you decided on the topic of your graduation thesis?"

"Think about it, I'm going to develop a new type of compression software."

"What new method? Lossy compression or lossless compression?"

"Lossless compression, I am going to improve the LZ77 algorithm and design a software with a higher compression ratio than PKZIP."

Liu Shaosong was a little surprised when he heard the words, looked up at Di Ye, and reminded: "The LZ77 algorithm is not so easy to improve, are you sure?"

"I've roughly figured it out, and I should be able to write the software during the winter vacation."

The old man sitting across from him sneered, and said sarcastically, "Students nowadays are getting more and more out of control. They want to write better software than PKZIP before they graduate from undergraduate course. Be careful that you won't be able to graduate if you boast too much."

Di Ye didn't know this old man, so he didn't bother to pay attention to it, but Liu Shaosong responded tit for tat: "People are not frivolous, and it is not a bad thing for college students to be high-spirited."

After he finished, he pointed to a stool by the window and said, "Di Ye, sit down and tell me how you plan to improve the LZ77 algorithm."

Di Ye took out the manuscript paper from the kraft paper bag and said, "I plan to add interval coding based on Markov chains to the LZ77 algorithm and the Deflate algorithm..."

Last night when I heard that Liu Shaosong was looking for him, Di Ye felt that it must be related to his graduation thesis, so he discussed the rental house with Di Ye, and then chose the compression software as the first shot he made famous in 1995.

In the 90s, the network speed was slow and the hard disk was small. Almost every computer had to install compression software, which was used in a wide range of scenarios. However, most compression software on the market at this time was charged, and the algorithm was also protected by patents. If you were not careful, you could easily get a lawsuit. For example, in 1993, Microsoft lost 1.2 million US dollars because of a compression algorithm called LZS.

The LZ77 algorithm is the basis of the lossless compression algorithm. It was invented by Abraham Lempel and Jacob Ziv in 1977. After that, many improved versions were derived, the most famous of which are Deflate and LZMA.

The Deflate algorithm was invented by American programmer Philip Katz in 1988. He used this algorithm to develop PKZIP. PKZIP later derived the famous WinZIP and became the king of compression software in the 90s. Although it declined after 2000, the zip file format it left behind was still widely used until 2023.

The LZMA algorithm was invented by Russian programmer Igor Pavlov in 1998. He used this algorithm to develop 7-ZIP, which is famous for its high compression ratio and fast speed, and it is free and open source. After its release, it became very popular and soon became one of the mainstream compression software.

What Di Ye described to Liu Shaosong was the LZMA algorithm. He couldn’t do it practically, but he had a good eloquence, and he was a loyal user of 7-ZIP before crossing. He had studied its code when he was in college, and he knew this software very well.

Liu Shaosong only listened for a minute or two, then put down the mouse, turned around, and communicated with Di Ye face to face. After listening to it, he read the manuscript paper in detail, and then applauded and said, "Di Ye, you are very talented in the field of computer algorithms. The introduction of Markov chains is a very clever idea. If it can be realized, the paper you write will not only graduate from a bachelor's degree, but even a master's degree will be fine!"

"Software is written, not blown."

The old man on the opposite side felt a little uneasy on his face, said something eccentric, and then walked out of the office with a thermos cup in his hand.

Liu Shaosong shook his head and smiled, and said, "Don't worry about him, he's an old bastard, he only teaches courses like "Introduction to Computer Basics", and he doesn't understand what you just said at all."

Di Ye hummed and asked, "Teacher Liu, do you have anything else to do with me?"

Liu Shaosong got up and went around the desk, closed the door, and said with a serious face, "I went to your dad's store on New Year's Day to buy some phono CDs. He was in good health and was not sick at all. You told Dean Fei yesterday that he was sick and gave Shi Yucheng his internship at IBM. What's going on?"

Di Ye is a big fool, and he didn't panic at all when he was exposed. He put it another way: "Mr. Liu, Shi Yucheng and I are both locals in Yuncheng. His family is rich and powerful, and my family is ordinary. If I don't give him the internship quota at IBM, I'm afraid not only I won't be able to take the postgraduate entrance examination, but I will even hurt my family. Instead of fighting with each other and losing both ends, it's better to sell favors. After all, the postgraduate entrance examination is my primary goal."

Liu Shaosong was merciless at the old man just now, like a person who is not in harmony with the world, but now he was very calm, frowning and asked: "Did he threaten you?"

"Not on the surface, but secretly engaged in a lot of small tricks."

Liu Shaosong sat back on the chair, pondered for a while and said, "That's fine, you can concentrate on taking the postgraduate entrance examination. With your talent, continuing to study is more promising than finding a job."

After speaking, he pointed to the stack of manuscript paper, and encouraged him: "This compression algorithm is very technical. It should be published in SCI journals when written. It will be very helpful for your postgraduate entrance examination re-examination. You should think about it during the winter vacation and try to make it perfect. I will not go back to my hometown this year. I will spend it in Yuncheng. If you encounter any problems, you can come to me at any time."

"Okay, thank you Teacher Liu."

The office building where the School of Computer Science is located is facing the stadium. After Di Ye came out, he saw a lot of people playing basketball. On a whim, he ran over and played a few 3V3 games with them, making him sweaty. Since the student dormitories and the Tongzi Building didn’t have water heaters, if he wanted to take a bath, he had to wait until the public bathhouse opened at 1 p.m.

"No credit card or her, no home with 24-hour hot water..."

Di Ye repeatedly hummed these two lines of lyrics, picked up the kraft paper bag from under the basketball hoop, and was about to go back to the dormitory to find some clothes for a change of clothes. He went to an off-campus hotel to open an hourly room to take a bath, but just after walking a few steps, the BB player in the bag rang.

According to Di Ye, Huang Ya and him were classmates from junior high school to high school, and they had been at the same table for a while. They belonged to childhood friends, so they couldn't ignore it. Di Ye found a small shop with a public phone nearby, and dialed the number on the BB machine.

"Di Ye, treat me to a big meal at noon, you promised yesterday."

"Please tonight, I just sweated playing basketball and I need to take a shower."

"Playing basketball? Don't you just like playing football?"

Di Ye didn't expect sports to reveal his secrets, and said with a wry smile: "No one played football in the morning, so I went to play basketball for a while to exercise. It's fake if you ask me for dinner, but it's true if you have something to do. Tell me, what's the matter?"

"Xia Fangfei said that you have changed. You are a different person from before. Your skin is very thick and your mouth is very poor. I went to buy a gossip mirror to see if you have been possessed by some dirty thing."

"I know you peed your pants in junior high school, and I know who you had a crush on in high school. Don't force me to fight you to the death."

"Oh, it's over, Di Ye, you must be possessed by something dirty, otherwise you wouldn't be so vicious."

"goodbye!"

(End of this chapter)