In the afternoon, Cheng Nuo and Wang Gengen went to the largest library in Kyoto to sweep up.

With a huge sum of 1,000 yuan in their pockets, they looked full of pride.

"Engineering Mathematics", which has information about how the Helmholtz equation system is constructed, bought it!

Acta Mathematica Sinica, which contains several papers on the Helmholtz equation in the next dimension of polar coordinates, was also bought!

"Research in Advanced Mathematics", which has a chapter on the higher-order difference format and algorithm of wave equations, buy them all!

"Young Abin" mainly tells the legendary life of Abin, whose high school grades are not ideal, and has a good learning significance for them. So Wang Genji pulled Cheng Nuo to buy a full set of upper and lower volumes.

By the way, I also bought an inspirational book about a woman named Baijie, which is worth reading when we lie in bed at night.

"It's really heavy!"

Wang Genji shook the heavy stack of books in his hand and couldn't help but speak.

Check out, go!

There are more than 20 books, and the total cost is more than 500 yuan. Then the two bought some necessary stationery such as whiteboards, scratch paper, gel pens, etc., from a nearby stationery store.

When it was over, both of them carried heavy things in their hands.

And the project fund of 1,000 yuan, there are more than 300 left. And that's the result of them buying a lot of stuff.

Sure enough, people in the mathematics department are really quite economical when doing projects.

1,000 yuan, put it on other projects, I'm afraid it won't even make a wave. But for math topics, as long as they are given a pen and paper, and sometimes a computer, everything can be solved.

The sun was still poisonous on the October afternoon, and the two wiped the sweat from their foreheads and stood on the side of the road waiting for the bus.

At this time, a moving song sounded in the ears of the two.

"Grilled gluten, grilled gluten ~~"

"My baked gluten!"

"Makes you happy every day when you eat~"

"Grilled gluten, grilled gluten ~~"

"Let you eat at a real price!"

An uncle with dark skin, watermelon-covered hairstyle, and a blue and white coat pushed a stall with roasted gluten and came to the two.

"Guy, how about a few skewers of grilled gluten?" Brother Gluten asked the two enthusiastically.

The rich aroma of the smeller. Wang Gengen swallowed his saliva.

Baked gluten, that's a good thing!

"How much is a skewer?" Wang Genji asked as he walked to the stall where he roasted gluten and swallowed his saliva.

"Two yuan a string, absolutely affordable!Guy, how many strings do you want?"

"Bring me eight skewers, by the way, do you have a drink here, and get me a bottle too." A little thirsty. ”

"Yes, yes. ”

Brother Gluten handed Wang Genji the eight sticks of gluten sprinkled with seasoning and a bottle of drink.

"Ahh

Wang Genji took a bite of gluten, with an intoxicated expression on his face, and gave a thumbs up in praise, "Boss, you baked gluten, two words: delicious!"

Wang Genji couldn't help but take a big bite again, stuffed the gluten whole into his mouth, puffed out his cheeks to chew, and said inarticulately, "Boss, since the baked gluten you sell is so delicious, why don't you go to the gate of those schools to buy it, it should be more profitable over there than selling it here, right?"

"Hey, you don't know. I'm unhygienic, I can't give it to children!" said Brother Gluten with a conscience in the industry.

Wang Genji stopped chewing in his mouth and looked at the lone stick left in his right hand, "......"

What the hell am I ...... It's still a kid too, wow!

"Senior Foundation, the car is coming!" Cheng Nuo waved his hand to Wang Foundation.

Wang Genji was no longer entangled in the question of whether he was healthy at this time, and while taking out the money from his pocket, he asked, "Boss, how much is it in total?"

"Eighteen in total, you can give me twenty directly, no need to look for it. ”

"Good. Come, here you go. With that, Wang Genji handed a 20 yuan bill to Brother Gluten, and then hurriedly walked to the called car, opened the door and got into the car.

A few minutes later, a wail erupted from a car that had been far away.

"Sister, Lao Tzu is from the Department of Mathematics, and he was cheated for two yuan by buying gluten!"

............

Because of the "two yuan" incident, Wang Genji, who has always claimed to be a mathematical genius, looked sullen all the way. It's even a little skeptical about life.

Back at school, because Cheng Nuo didn't know where the dormitories of the other two seniors were, Senior Wang Genji was even more hollow-eyed, and it was almost impossible to recover from the blow just now for the time being, so he could only put the books and stationery he sold back in his dormitory.

"it!Cheng Nuo, didn't you just come back from robbing the bookstore?, why did you buy so many things?" Seeing the large pile of things that Cheng Nuo got back, Yuan Hua couldn't help but make a fuss.

Cheng Nuo wiped the sweat from his forehead and smiled proudly, "Of course it's studying! I don't want to be like you, indulging in the world of eating chicken and can't extricate yourself." I was a good student who loved to learn. If I don't study for a day, I'm all overwhelmed!"

Yuan Hua: "......"

Hehe......

I don't know, when I ate chicken a few days ago, who was the person who had the most fun and called on everyone to play all night together?

"Come, bother my brother, there are still things that haven't been brought up below, do me a favor." Cheng Nuo took a few sticks of baked gluten that Senior Wang Genji threw to him when he got off the bus as compensation.

"No problem. The three of them ate roasted gluten while going downstairs with Cheng Nuo.

............

The sixth day of the National Day.

When most of the students were still enjoying the wonderful National Day holiday, Cheng Nuo, who was forced to devote himself to the research of the project.

The first part of Cheng Nuo's responsibility is to introduce a linear system of two-dimensional Helmholtz equations through the one-dimensional Helmholtz equation combined with the compact difference format.

Of the five parts of the project framework, this is the simplest part. So Jiang Shuobo handed over this task to Cheng Nuo, who was the youngest in the grade.

At the same time, the first part is also the most basic part of the whole project.

If Cheng Nuo's side had not even calculated the linear system obtained by the discrete two-dimensional Helmholtz equation in CCD (Joint Compact Difference) format, the work of the next four parts would not have been carried out at all.

After all, the title of this project is to study the CCD format of the 2D Helmholtz equation!

It's a lot of pressure!

This is the first time Cheng Nuo has received such a high-level task.

However, as the king of the three good forces in the new era, Cheng Nuo felt that it was incumbent on him to complete the task of blocking him perfectly.

So today, Cheng Nuo got up early in the morning. Get ready to start his day in research.

In order to pretend to be forced, Cheng Nuo has to do his best.

The dormitory environment is too noisy, the library is too far away, and there are too many loving dogs, Cheng Nuo is worried that he will not be able to accept that psychological gap.

So Cheng Nuo came to a ...... near the school alone Internet cafe. I opened a machine.

Then, under the confused eyes of everyone eating chicken in the Internet café, he slowly took out a piece of treasure from his schoolbag.

Scratch paper, gel pen, compass, eraser......

Discrete Mathematics and Its Applications

Proof and Refutation - Logic Found in Mathematics

Application of Richardson's extrapolation method

............