"Discrete mathematics is a mathematical discipline that studies the structure of discrete quantities and their interrelationships. Discrete mathematics can also be said to be the basic core discipline of computer science. At the same time, discrete mathematics is a bridge built between mathematics and computer science."
These two sentences were the explanation of Discrete Mathematics that Xing Conglian had just found. He read it out loud, and was interrupted by the dynasty.
"I am familiar with discrete mathematics, why do you still want Baidu, boss, do you look down on me!"
"Then ask Wang Xiansen, why did Jin Xiaoan glance at "Discrete Mathematics" on the bookshelf when Fu Hao mentioned 'Jiang Liu'?"
"How do you know that she is reading "Discrete Mathematics"! It may also be the book "Everything Starts From Meeting" next to it?" Chao asked rhetorically.
"Because we also found the same book of "Discrete Mathematics" belonging to Xu Haozhen in Wang Shishi's dormitory..."
"God horse?" Dynasty shuddered, "Unbelievable!"
"Speak well!" Xing Cong patted the boy on the head.
"Come on, "Discrete Mathematics" is not advanced mathematics, it is not a compulsory course for colleges, and they are not from mathematics or computer science, right? Why are you suddenly interested in this?"
Hearing Wang Chao chattering in his ears, Lin Chen lowered his head and looked at Professor Fu who was chatting awkwardly with Jin Xiaoan on the screen. What they said in the conference room probably all fell into Fu Hao's ears through the microphone, so Professor Fu's face now His muscles were stiff, as if he didn't know what to do next.
"Professor Fu... Guess, will Jiang Liu's name be written on the title page of Jin Xiao'an's Discrete Mathematics?" Because of his words trembling.
However, the only way to verify the guess is to do it.
This time, instead of embarrassing Hao, he said, "Don't you have a file bag under your arm, hold a cigarette case with the other hand, pretend to read the book "Everything Starts with Encounter", and then pretend not to Be careful, take out discrete mathematics as well." Fu Hao could only use 0.1% of his usual speaking ability when facing girls again, so he continued, "You can say to Jin Xiaoan: ' You also read everything, and I also read this mystery novel.'"
In short, although the level of the director is not high. But fortunately, Fu Hao acted in an embarrassing manner from beginning to end, so neither his introduction nor the next action of taking the book off the shelf was unexpectedly not abrupt.
Several books fell to the ground. Fu Hao hurriedly squatted down, blocking Jin Xiaoan's sight. He first put a certain reasoning book back on the table, and said, "This book is really good, have you read it yet? "
Then, pretending to be inadvertent, he quickly flipped through the book of "Discrete Mathematics", holding a cigarette case in the other hand, and photographed the process of flipping through the entire book, with a very dedicated attitude.
"Is this "Discrete Mathematics" the same as Wang Shishi's?" Dynasty manually slowed down the screen, dragged the progress bar forward, and asked.
"Same." Lin Chen stretched out his finger and gently drew a circle on the screen.
In the lower right corner of the title page of the book, the name "Jiang Liu" really appeared.
"Pay attention to take a photo of the copyright information page, and then you can retreat." After Lin Chen finished speaking, he turned off the microphone.
The meeting room was quiet, Lin Chen didn't speak, Xing Conglian didn't speak, and even Captain Jiang, who was usually carefree, didn't dare to speak.
Therefore, the only one who dared to speak under such circumstances was the dynasty.
"Is this a sorority, and also send books to each other to urge each other to study hard?"
The boy's voice was sweet and sweet, although this question didn't have much effect, but just listening to the voice of the dynasty made one inexplicably relaxed.
"Can you explain discrete mathematics a little?" Lin Chen asked.
"I can't explain it to you. The subject is too big and the content is too much. It's too difficult for you." Although the main idea of this sentence is to say "you mortal IQs are too low", the sincere eyes of the dynasty let him People didn't even have the strength to knock him on the head.
While they were talking, Xing Conglian followed Fu Hao seriously after reading the original discrete mathematics, and suddenly said, "It's a bit strange."
"how?"
"Look, this book is a little old, but it doesn't have any marks on it..." Xing Cong pointed to the curled corner of the book and said, "The book Xu Haozhen gave to Wang Shishi is the same, although it has been turned over. Many times, but without any obvious reading notes on the book."
"What's wrong with no notes, a normal person can't stand reading 10 pages of this kind of book?" Wang Chao said.
"Then ask Wang Xiansen, why do you turn a book that normal people can't stand reading 10 pages to rotten?" Xing Conglian hooked Wang Xiansen's neck and asked with a smile.
At that moment, the young comrade of the dynasty had an epiphany, three flowers gathered, turned his head and said to Lin Chen, "Achen, the boss asked you!"
Lin Chen was amused by him, and the original foggy situation suddenly became clear: "The book has been turned over, it can only prove that someone has turned it over many times, but it can't prove anything else."
"Can't prove anything?"
"I can't prove it, whether it's Jin Xiaoan or Wang Shishi, they have read this book seriously..." Lin Chen glanced at Xing Conglian, and added, "For professional books like this, most people who read them carefully will read it. Take notes in the book while watching…”
"But it's also possible that this book is so precious to them that they are reluctant to paint!"
Seeing that the Dynasty would draw inferences from other facts, Lin Chen nodded in relief, and said, "It is indeed the case, so now there are two possibilities. First, they have not read the book "Discrete Mathematics" seriously, but they have just read the book. After flipping over and over again, what exactly this subject is talking about actually means nothing to them. Second, they have studied "Discrete Mathematics" seriously just because they cherished this book too much and did not take any notes on it... Which do you think is more likely?"
Wang Chao scratched his head: "I don't know! But let's be honest, I'm not a math or computer major. Learning "Discrete Mathematics" is too difficult, and the founders of set theory are crazy..."
"So you agree with point one?" Lin Chen interrupted the boy's words.
"A Chenfan, I think you're right!" Chao Dynasty said to him very spinelessly, "So the answer is that they really don't understand shit, are they flipping through the book?"
"yes."
"But how do you know?"
"Oh, because you just showed me Jin Xiaoan's file, which contains her university transcript. She failed the high school math." Lin Chen said.
Hearing this, Comrade Wang Chao quickly took a deep breath, and then said sadly to him: "Achen, don't learn from the boss, it's not good..."
"Conscientiousness is very important in the process of handling a case." Xing Cong even knocked on the dynasty, educating him, "and having studied discrete mathematics is nothing to show off."
"But why, what kind of qigong are they practicing? Flip through the book and change the meaning of it?" Wang Chao asked depressedly.
"If you add several other keywords in this case, such as 'dark network' and 'drugs', do you have any associations with this?" Xing Conglian continued to ask.
In an instant, Wang Chao's eyes changed: "Damn, boss, I'm going to be terrified, what are you thinking about tonight!"
As soon as the boy said this, the whole room fell into an unbearable silence.
Lin Chen clenched his right hand tightly and fell into silence as well.
A rotten book, a group of college students, a controlled group, a dark webcast, a drug deal, a jewelry heist…
If these keywords are connected in series, it is roughly like this: Some people have controlled a group of college students through some means, not only using them to conduct various online live broadcasts to make huge profits, but may even involve hundreds of millions of yuan in jewelry robbery and transnational The drug case, and the only clue they have now is that each of these students seems to have a strange "Discrete Mathematics" in their hands.
Then, the role of this book seems to be obvious.
"What the hell is going on, I found that you don't like to explain the vernacular." Jiang Chao finally couldn't help breaking the silence that was too tacit.
"Let's put it this way, why did the murderer behind the scenes use the dark network to broadcast live?" Chao asked back.
"In order not to be found out!"
"Yes, whether it is an onion server or a dark network, it is essentially a service to protect personal privacy. In other words, it is an encryption method, so if someone controls a large group of students, does he need to give these children a subscription? Command, then, he must also ensure that the information he transmits has a certain degree of security, right??"
"Isn't it, do you think that book is a codebook, what age is it now, you still play with this kind of thing, and this book has not been found in the relics of other deceased people?" Jiang Chao responded quickly and continued: "And don't they have a dark network, so on the Internet, isn't it more convenient to have a dark forum or something to communicate?"
"Oh, it's very simple. Don't the organization recycle this important thing before it dies? Is the criminal organization stupid? Can you keep such an obvious clue for you to check? It is estimated that Wang Shishi's book must be due to some special reasons, so there is no Destroyed! In fact, although this encryption method is very simple, it is actually quite useful and hidden. First of all, even roommates, very few people will read books such as "Discrete Mathematics". It's easy to be suspicious. Then, mass text messages, WeChat, etc. are more likely to be traced, and math books have many formulas and strange characters. For example, if I report a number 1612, you Do you know if I am talking about 16 pages and 12 lines, or 1 page and 6 lines and 12 words. If that word happens to be a minus sign, do you know that it means backspace, carry or delete? Of course, this encryption method is theoretically possible. It can be cracked, but it requires a lot of data and operation analysis. Therefore, a math book can really be used as an ideal password manual... The reason why I think it is ideal is because, except for my boss, who the hell knows? Link a good book to the underground cryptographic work!"
"I think you are complimenting me." Xing Conglian said coldly.
Finally, the team leader Ren, who had been hiding in the corner, suddenly became interested in this topic. But rather than interest, it was his primary concern: "You mean, they use this Discrete Mathematics as a cryptographic manual for passing information? I think the reason you can think of this is , I'm afraid it's because this encryption method is an underground criminal organization, and to be precise, it is a method that drug dealers like to use, so I can doubt that these students are actually being secretly used to deliver drugs?"
"You can doubt like this, but such doubts are basically useless now." Xing Conglian said extremely coldly.
"You can't stop my investigation because of your own case!"
"I seem to have said that everything related to Fang Zhiming's drug factory case is not within the general direction of our detection for the time being?"
"This is a major clue, we can follow it up!" Ren Xian raised his voice abruptly.
"Oh, has the team leader ever intercepted any passwords?" Xing Conglian was still indifferent, but his words made Ren Xian speechless.
"Not yet, but I can review the file, maybe there will be clues..."
"Okay, if you were lucky enough to intercept a string of passwords, and then your conclusion is verified, someone manipulated a group of students to carry out countless illegal and criminal activities, including using them to sell drugs, and then, you can use this to catch the murderer or save the Are these children?" Xing Conglian's voice was cold, he stretched out his hand, pointed at Dynasty's laptop, and the picture was fixed on the girl with her head bowed in the seat, "You still don't understand, this case and the ones we encountered before. Does homicide make any difference?"
"I..." Ren Xian hesitated, apparently not trying to understand the question.
"What's the difference?" Jiang Chao also interjected.
Lin Chen looked at the criminal police captain who was obviously annoyed by the two of them, and couldn't help but patted the back of his hand and explained for him: "The difference is that in ordinary murder cases, we just need to find the murderer, but in this case, Even finding the culprit behind it is not the first important thing."
"Isn't it important to catch the culprit behind the scenes?"
"Compared to the imminent bloodshed and a group of manipulated college students, it doesn't matter who is behind it and what he's doing with these students, it's how to solve the problem that matters most."
After Lin Chen finished speaking, he looked at Xing Conglian again.
In fact, if he hadn't explained it himself, he wouldn't have found out that Xing Conglian's thinking has always been clear, the priorities, and which comes first, he couldn't be more correct.
It was so right that he was speechless.
"Isn't that the quickest solution to find the murderer and let him stop?" Jiang Chao asked again.
"We now have two clues available, a book and a person. Suppose that discrete mathematics is really a cipher table, but we have not even intercepted a corresponding cipher, this clue is basically useless now, and gold Xiao An... You didn't pry open Cheng Weiwei's mouth that day, so when you see Jin Xiaoan today, do you think you can pry open her mouth and get any useful information?" Lin Chen continued.
"Then we still have a dead end?" Chao Dynasty raised his hand sadly and asked.
"Who said that?" Xing Conglian picked up Chao Dynasty's ear and said, "First of all, compare Wang Shishi's discrete mathematics and Jiang Liu's book to see if they are of the same edition, then check the copyright page to find the publisher to see the print volume and Check out the library records to see how many books have flowed to Hongjing, do you want me to teach you about this kind of thing?"
"This kind of trivial matter is on me..." Chao Dynasty patted his chest and his hands were flying, "Look at the version first!" The first printed version in 2001 has a print run of 5,000, which means it's really an antique!"
"The advantage of the old book is that it may not be sold online anymore..." The teenager hit enter and sighed: "Bingo, it's really not sold online, sir, I don't know how to evaluate your luck. ."
"So, is luck good or bad?" Xing Cong asked boredly.
"It has not been sold online, which means that it is through the channel of the publishing house. The advantage is that I can check the publishing records of the publishing house. The disadvantage is that the time period is too long, and there may be multiple distributors in different batches. I ordered this book, and any system can only find first-level dealers, but not second-level dealers, so... "
The young man stopped the ending abruptly.
Although he made a lot of assumptions, after he set the search conditions and the search was over, only one dealer's name appeared in the entire Yongchuan City.
[Key point of Yongchuan Siyuan Inspirational Book Distribution Co., Ltd. Chang Wei 139XXXXXXXX]
At this time, Jiang Chao also handed the pictures of the mobile phone to the dynasty.
The teenager glanced at the photo, quickly copied the bookstore address, and sent it to his boss: "The two books are the same version, the address has been sent to your mobile phone, boss, you can go, bye bye!"
The time is 8:31 pm.
Lin Chen first looked at the time displayed on Xing Conglian's mobile phone, and then looked at the address. He found that the dealer's location happened to be in the book market of Yongchuan University, so he said: "Phoenix Book City is usually at night. It won't close until nine o'clock, so drive a little faster and you should be able to catch up."
Xing Conglian had already turned around and was about to go out. Hearing his words, he turned around abruptly and said to Ren Xian, "It's nine o'clock, so the jet lag parties on the other side of the ocean are probably getting up soon, please let the team leader keep an eye on them, If there is anything on the Internet, you can just tell this kid to do it." After he finished speaking, he pointed to Wang Chao's head, as if he was worried, and then ordered, "Don't do any communication with those people, they provide useful information. , we'll give the money, that's the fastest way."