In the middle of the night, I almost beat myself ten years ago

It was almost midnight when Zhang Dafang left the company.

At this time, the moon in the sky still exudes a cold gloom, looking at the earth mercilessly.

Recently, the company's business is busy, and a large number of technicians are forced to work late at night. Zhang Dapang is one of them.

There is a long queue of taxis lying around the company’s door. Even taxi drivers know that this is the peak time for the park and it’s the easiest time to work.

Zhang Dafang got into the car and skillfully took out the laptop from his backpack.

"There will be an interview tomorrow night. I have to hurry up and make up for the technical foundation." Zhang Dafang thought.

Zhang Dafang didn't notice, the driver in front glanced at the rearview mirror and sighed slightly.

The driver is also a fat man. He looks about 10 years older than Zhang Dafang. The looming hairline inadvertently reveals the crisis of middle-aged people.

What Zhang Dapang reviewed today is the CPU cache. While looking at the pictures on the computer, he recalled his previous knowledge and muttered to himself:

"CPU Cache" refers to a high-speed memory whose access speed is much faster than that of general memory, mainly to solve the problem of the mismatch between the CPU operation speed and the memory read and write speed. ..... "

Zhang Dapang found that his mind was a little uncomfortable because of working overtime and staying up all night.

"Young man, you are a computer engineer. It's too late, don't work hard anymore, your body is important!" A vicissitudes of speech came from the front seat.

"Thank you, Master. Tomorrow night is the interview with Forty Thieves Company. I have to fight hard and enter the big factory!"

"How about entering a big factory? What does it mean if someone arranges the interview in the evening?"

"Oh! It means you are working overtime!" Zhang Dafang was a little surprised. The driver seemed to know a bit about the IT industry.

"However, as long as there is more money, it is worth it to be tired. It is impossible for a person like me without background to gain a foothold in a big city without suffering." Zhang Dapang added.

The driver was silent, holding the steering wheel firmly, looking into the distance.

Zhang Dafang's eyes were also attracted by the pictures in the laptop.

After being silent for a while, the driver suddenly said: "By the way, I have a relative who writes code in a startup company. What is it called dancing? The development momentum is very good and it is hiring people. Would you like to go?"

He turned his head, his eyes lightened and added: "If the company goes public, you will be financially free!"

"Master, be careful of the car ahead," Zhang Dapang reminded him immediately when he saw that he was not looking at the road.

"What are you going to do? A startup company will die for nine years, and the risk is too great." Zhang Dapang wanted to be stable and wanted to enter a large company.

"Young man, it's a pity not to take risks!" The master in the front seat shook his head helplessly.

Zhang Dafang thought to himself, why should I trust you? You said financial freedom can be free? It might be a waste of my youth!

"By the way, I heard that there is a bitcoin now, you programmers should understand, you can buy a little!"

Zhang Dafang grinned. He didn't expect this master to be very informative and even knew Bitcoin.

"Master, you may not understand. I have studied Bitcoin. What Hash and what decentralization are all digital games, without any value!"

"Oh, now it seems like a few cents, you can spend a hundred and ten yuan, buy a few thousand bitcoins for fun! Hoarding for a few years will definitely increase the price!" Hearing Zhang Dafang's disdain, the master seemed a little anxious .

"Haha, it would be better to have a buffet with my classmates!"

After Zhang Dafang finished speaking, he lowered his head to look at the CPU cache.

After the car drove for ten minutes, the master said quietly: "Young man, are you going to stocks? I can recommend a few potential stocks for you, such as Tencent, Ali, Moutai, Gree, Microsoft, Apple..."

"Master, you are so amazing, all the stocks are going to the U.S., but I don't stocks, I'm scared every day, I can't stand it!"

"These are all potential stocks. You can hold them for a long time. The income is definitely more than a few times. You won't have to work so hard in the future!"

Zhang Dapang smiled and said that this Beijing-based driver master can really brag. In the stock market, he can't be the lucky one.

He pulled his thoughts back to the CPU cache and began to review the three methods of address mapping, direct mapping, fully associative mapping and group associative mapping.

"Then you buy a house? The house in Beijing is now at the lowest point. As a super metropolis, Beijing's future housing prices will be like Hong Kong's, tens of thousands per square meter."

"Master, you are joking. Now we young people can't afford it for tens of thousands of yuan, and we still have hundreds of thousands. Who will sell it?"

"Squeak---" Suddenly he braked, shocking Zhang Dafang.

The driver master opened the door, dragged Zhang Dafang out, grabbed Zhang Dafang by the collar and shouted, "I really want to beat you up. I pointed you to several bright roads. Why don't you go? Go to squeeze that single-plank bridge?!"

Zhang Da Pang was stunned for a moment: "Master, we two seem to have nothing to do...Be careful of my 16-inch top with MacBook Pro, which is very expensive..."

The taxi master's expression slowly eased, and he sighed deeply: "Oh, I'm so stupid!"

He released Zhang Dafang and returned to the car to continue driving.

Now you can see the tall buildings in the community. There are not many buildings with lights on.

Uncertainly, Zhang Dafang began to pack his things and get out of the car.

"Young man, it is indeed commendable to study technology firmly, and you will definitely gain something if you stick to it, but I want to give you a few suggestions:

1. Do not just focus on technology, but also get the business done. Let technology serve the business, which must generate business value.

2. You have to find ways to increase technological influence.

3. In addition to technology, we must develop another field to form cross-over advantages

4. .....”

Zhang Dapang thought to himself, this master is really long-winded, and he interrupted the master unceremoniously: "Thank you, master, I have read a lot of these principles on the official account of the programmer, and I will follow them."

"Also, embrace uncertainty and try more things that are low investment and may have huge returns, such as..."

"Thank you, Master, for your concern!" Zhang Dapang was indeed a little impatient.

The driver's master gave Zhang Dafang a business card: "You can contact me later!"

Zhang Dafang didn't even look at it, so he threw it into his bag and got off the car with payment.

Behind him came the shout of the master: "The LRU algorithm is the most commonly tested in the CPU cache. Handwriting is required during the interview..."

Without looking back, Zhang Dapang walked home quickly and escaped from this long-winded "Tang Monk".

The next night, during the interview with the Forty Thieves Company, the interviewer had to write the LRU algorithm by hand, as expected by the taxi driver.

Zhang Dapang was well prepared and passed smoothly.

When Zhang Dafang came home, he quickly turned out the business card, and saw three big characters: Zhang Dafang.

There is also a line of fine print: I am you ten years later

Zhang Da Pang was shocked. He desperately recalled the content of the conversation with the taxi driver last night, but it was like a dream. He couldn't remember anything...

(Finish)

Postscript: This article is authorized to be adapted from the article "In the middle of the night, Didi driver asks me whether I can LRU?" ". Account owner An Jiang, currently working for Douyin, often shares his knowledge and technical understanding of the Internet industry in his personal public account. Very hard-core technology, very warm storytelling. Many readers say that reading his articles is as comfortable as rolling under a bed.