Without any delay, the next day, Han Sen began to soak himself in the library of Tsinghua University.

After ten years of sharpening his sword, Han Sen always laughed at himself for only getting five degrees from Princeton University after ten years of studying, but in fact, in these ten years, his biggest gain is his thinking ability and his brain.

The library of Tsinghua University is still very powerful, with a very rich collection of all kinds of books.

The most classic textbook for topology is "Topology without tears", which is vividly typeset and relatively simple.

In the mathematics area, Han Sen quickly found this book, a thick English book has been yellowed by students one by one, this is the power of Tsinghua "scumbags", the yellowing degree of the whole book is homogeneous, which shows that basically all the students who borrowed the book have "gnawed" from the first page to the last page, rather than being persuaded to quit after reading the first few pages.

Excellent books are always worth reading repeatedly, every time you read it, there are always some new ideas, Han Sen has always maintained this moment of awe for some classic books, although this introductory "Topology without tears" is relatively simple, but Han Sen read it seriously.

In the library, while reading a book, Han Sen simply checked on the scratch paper, greedily absorbing the knowledge in the book like a sponge absorbing water, and combined with the knowledge system in his brain, he began to enrich the topology-related architecture.

......

In the quiet library, only the sound of the "Xiaoxiao" pen tip rubbing against the white paper, when many university students are lying in front of the computer to play games, Tsinghua students are faced with endless paper.

The sunlight through the glass windows is great, and perhaps the sun is especially happy to see this group of young people who are striving for progress.

......

In any discipline, different scholars write the same textbooks with their own different thinking, although the core content of each textbook is roughly the same, but different scholars have different thinking, and the textbooks they write are actually very different, and each textbook is a thought, so what Han Sen has to do is to read all the classic textbooks on topology, and then ferment and sort out the entire topology system in his own brain.

At the end of the day, his mind was full of mathematics, and the strong mathematical inertia occupied Han Sen's brain, and on the way home, the distance and speed outside the car window were decomposed and analyzed by unconscious data, and the accelerator and brake were accurately controlled, and finally Han Sen accurately parked the car in the parking lot of Wanliu Academy.

......

Because he had just returned to China, Han Sen chose to rent a house, and after a simple selection, Han Sen chose Wanliu Academy, which is very close to Tsinghua University, and also close to the Wanliu Campus of Peking University, and close to the headquarters of the Wanliu Martyrs Brigade. Therefore, many people with lofty ideals have succumbed to the great cause of "basing themselves on Yanyuan and liberating Tsinghua University", and as a member of Tsinghua University, Han Sen will of course break into the enemy.

Push open the door, the big three bedrooms of less than 300 square meters, there is no such empty and deserted large flat floor, and it will not appear crowded in layout, with light luxury decoration, it has a very good taste of life, and it is very close to the school, Han Sen likes this house very much.

Nearly 200,000 square meters of the big three-bedroom, should be regarded as a "golden house", and the key is that Han Sen pushed open the door, a very beautiful girl with bare feet stepped on the floor of the kitchen, a simple loose shorts, perfectly showing beautiful legs, the top is a simple cotton suspender coat, reflecting the beautiful chest, natural beauty, not too much dress, it is charming enough.

"Ahem, cough~" Han Sen coughed dryly, he didn't know if he was fascinated by this girl who shared the house, or if this beautiful girl showed too much Han Sen was embarrassed.

Qin Jing, who was tasting the stewed beef brisket with tomatoes in the pot, smiled, looked at Han Sen who entered the door and invited with a smile: "Do you want to eat some together?" ”

Han Sen took off his delicate leather shoes, untied his bow tie, sat down at the table unceremoniously, and said to Qin Jing who was busy fiddling with dishes with a smile: "Have we met somewhere?" ”

The beautiful Qin Lan in the kitchen said with a disgusted face: "Big brother, such an old-fashioned conversation." ”

Han Sen shrugged, he really felt like he had seen this girl somewhere.

While eating, Qin Jing spoke: "You go to school in the future, can you take me for a ride." ”

Han Sen opened his mouth and asked, "You are also from Tsinghua?" No wonder I feel like I've seen you somewhere! ”

Qin Jing had a cute look on his face: "Big brother, come to trick me, I'm from Concord and have classes at Tsinghua University." ”

"Oh, little sister doctor!" Union Hospital and Tsinghua University are cooperating in running a school, Qin Jing has classes at Tsinghua University, Han Sen has no surprise, and jokes with a smile: "You are not afraid of not finding a boyfriend if you share a house with me like this!" ”

"You have the ability to sleep with me." The beautiful Qin Jing dragged his chin and said a playful word like a little devil.

"Ahem, ahem." Han Sen was taken aback.

Qin Jing said proudly: "Look, you can't sleep with me again, what impact does this have on me finding a boyfriend!" ”

......

In half a month, Han Sen read all the English textbooks on topology that he could find in the Tsinghua Library.

Next, Han Sen found out the topology of You Chengye of Peking University, and the textbooks written by the Chinese people are absolutely the most unfathomable.

Think about it, Han Sen read no less than ten various linear algebra textbooks when he was in Princeton, but in China, condensation is the essence, and scholars from the Department of Mathematics of Tongji University began to inject the knowledge of linear algebra into higher education in China with a thin booklet.

Han Sen has read Tongji University's "Linear Algebra" thin, it is really the essence, but it is too essence, it is not suitable for introductory textbooks at all, of course, if you can gnaw the Tongji version of "Linear Algebra", it is absolutely invincible to do the questions.

Day after day, Han Sen is in the library, in the cafeteria, and going home every day, at three o'clock and one line, a boring but very fulfilling schedule, of course, going home every day and chatting with a noisy and delicious little beauty is always the happiest moment.

In this way, for a whole month, Han Sen devoured all the topology books in the library, yes, this world, without Wiles, Fermat's conjecture has not been proven, but this has not affected the development of modern cryptography and topology, nor has it affected the development of the Internet.

It's all mutual, it's like if the tank doesn't appear on the battlefield, then the anti-tank weapon won't appear, and the same Fermat's theorem has not been solved, it has not produced a strong encryption ability, and it does not have a strong enough cracking ability, so it has not had much impact on the development of the Internet.